The Wiki Rule

"There's a wiki for that."

It's Rule 78: There is a Wiki of it. No exceptions.

There is no area of interest, no matter how narrowly defined, where a person cannot put up a wiki for it and attract at least a few editors with similar interests. Increasingly, in fact, there is a chance that someone already has put up a wiki for it. For example, here's one for cacti. The plants.

In the early days of the Internet, there was a similar phenomenon, the "everything has its own home page" rule. Anyone with enough HTML savvy and a powerful enough interest in one particular subject could and often would create a site dedicated to it. This was largely how the early Web was forged, in fact. All the stuff we know and love today—e-commerce, social networking—that came later. Except porn. Porn was there from the beginning.

With the advent of Wikipedia, the playing field changed. Rather than rely on a collection of sites each written by one person with questionable expertise, users could find most of the information they needed in an article written, edited, and fact-checked by an entire userbase of people with questionable expertise, but all on one easy-to-remember site. The interest in hand-crafted "fan sites" waned.

However, a number of factors kept Wikipedia from being a perfect replacement for the old system. A desire for greater detail on the topic than Wikipedia is willing to allow, for one. Schisms or differing schools of thought on the topic was another. Fan-made wikis sprang up to bring back the world of homemade sites with the added benefits of the wiki model.

The "wiki-sphere" is becoming a vast depository of information at all levels of detail. The encyclopedic wikis are collecting a great breadth of topics at an increasingly shallow level of detail, and the topic-intensive wikis are gathering all the details.

Not all Wikis are on the major search engines, though. Corporations use wikis behind firewalls, the American CIA uses one to collate data among agents and analysts, and even publishers of dead-tree books use them to coordinate edits among authors, editors and copy editors.

Fan-made wikis are usually made on wiki farms, such as Wikia, or else are hosted on a preexisting fansite. Recently, organisations such as NIWA have spoken out against the commercialization that takes place on wiki farms, and have encouraged fans to set up their own websites.

Wikis can reach truly huge sizes. To put them up as candidate for a Doorstopper is an understatement. See the list of largest wikis. Note: If you're looking for TV Tropes, they're on the list at the bottom. "All The Tropes" hasn't even been noticed yet. The first list only has MediaWiki wikis.

General

 * Alien Wiki: An interesting wiki documenting every alien species ever created in fiction.
 * Alien vs. Predator Central: An wiki/blog on the Alien vs. Predator series
 * Alternate History Wiki & AH.com wiki: For, well, Alternate History.
 * The Chaotic Neutral Wiki: A wiki devoted to chaotic neutrality in all its forms.
 * The Christmas Specials Wiki: Christmas-themed TV episodes and specials
 * Creative Sci-Fi Wiki: Wiki for people who like to create their own sci-fi settings.
 * The Cutting Room Floor: Dedicated to all those features that did not make the cut.
 * DozerfleetWiki: Dozerfleet Comics programs like Stationery Voyagers and the Ciem Webcomic Series.
 * DramaWiki: Asian live action dramas.
 * Emoticon Wiki: Emoticons.
 * Wikipedia Fakebandica: An index of Fake Bands.
 * Fictional Creatures Wiki: A work in progress wiki documenting every fictional creature that is not an alien.
 * James Bond Wiki: The James Bond franchise.
 * LOLCats Bible: The Bible if it were written in LOL Speak.
 * Poser and Daz Free Resources: Free content for Poser and DAZ Studio, filling the void left when Poserpedia disappeared. (Also All The Tropes' little brother - it's the second-largest English-language wiki hosted at the same hosting service as ATT, which is the largest.)
 * Romance Wiki: Romance Novels.
 * Super Powers Wiki: Almost, if not all types of extraordinary abilities that has ever been created in the world of Fiction.
 * TL Wiki: Translation Wiki, for Fan Translations of visual novels.
 * TYPE-MOON Wiki: The Nasuverse, Canaan and every other work affiliated with Kinoko Nasu and Type-Moon.
 * Urban Fantasy Wiki: Urban Fantasy.
 * Villains Wiki: For all the Big Bads, Dragons, Evil Geniuses, etc..
 * Vocaloid Wiki: Vocaloid.

Anime and Manga

 * Anime Bath Scene Wiki: It doesn't get much more straightforward than this.
 * Anime Boobs Wiki: A wiki about the various bust sizes of anime and manga characters.
 * Azumanga Daioh Wiki: Azumanga Daioh and Yotsuba&!.
 * Baka-Tsuki: Light Novel translation group since 2005.
 * Bee Train Fan Wiki: Combined Wiki and Community Forums for things related to anime production company Bee Train.
 * Berserk Wiki: Berserk
 * Black Rock Shooter Wiki: The Wiki for Black★Rock Shooter.
 * Bleach Wiki: The wiki for Bleach.
 * Blood Plus Wiki: Blood Plus.
 * Bulbapedia: Pokémon.
 * Pokémon Wiki, formerly known as the Pokémon Encyclopedia: Another wiki about Pokémon and established rival to Bulbapedia, using Wikia instead of Mediawiki. Much less organized than Bulbapedia and still under construction.
 * Cardcaptor Sakura wiki : Cardcaptor Sakura encyclopedia. Also includes plenty of info from Tsubasa Reservoir Chronicle and xxxHolic. The other two series also have their own wikis with huge overlaps between them - Tsubasa Reservoir Chronicle wiki and Holic Wiki.
 * Code Geass Wiki: Take a wild geass.
 * Darker Than Black Wiki: Darker than Black.
 * Deadman Wonderland Wiki: Deadman Wonderland.
 * Death Note Wiki: Death Note.
 * Death Note Fanon Wiki: Death Note Fanon and Fanfic.
 * Detective Conan World Wiki: Detective Conan, Magic Kaito and Gosho Aoyama's works.
 * Digimon Wiki: Digimon.
 * Alternatively, Wikimon.
 * Dragon Ball Wiki: the Dragon Ball series.
 * Duel Masters Wiki: Duel Masters, a Anime/Comic Wikia and TCG/OCG card database.
 * The Elfen Lied Wiki: Elfen Lied. Thorough, accurate series info for those who love the other Lucy.
 * Eureka Seven Wiki: Eureka Seven.
 * Eushully Wiki : Company-specific eroge mixed with other genres, such as strategy.
 * EvaWiki: Neon Genesis Evangelion wiki.
 * Fairy Tail Wiki: Fairy Tail.
 * Fooly Cooly Wiki: FLCL.
 * Freezing Wiki: Freezing.
 * Fullmetal Alchemist wiki: Fullmetal Alchemist,
 * Gantz Wiki: Gantz.
 * Gineipaedia: Legend of Galactic Heroes. Mainly covers the animated adaptation.
 * Gundam Wiki: Mobile Suit Gundam. All of it.
 * Haruhi Suzumiya Wiki: Suzumiya Haruhi.
 * Hetalia Archives: Axis Powers Hetalia.
 * Non-Wikia wiki
 * Higurashi no Naku Koro Ni Wiki: Higurashi no Naku Koro ni.
 * Infinite Stratos Wiki: A small, but growing wiki for the Infinite Stratos series.
 * Inuyasha Wiki: Inuyasha.
 * Kaijudo Wiki: The Kaijudo Wiki.
 * KanzakaDex: Slayers and other Hajime Kanzaka works.
 * Kekkaishi Wiki: Kekkaishi.
 * Keroro Wiki: Keroro Gunsou.
 * K-ON! Wiki: K-On
 * Kore wa Zombie desu ka?: Kore wa Zombie Desu ka?
 * Kurokami Wiki: Kurokami
 * Liar Game Wiki: Congratulations! You have been selected out of thousands of potential users to edit this wiki.
 * Love Hina Wiki: Love Hina.
 * Mawaru Penguindrum Wiki: Mawaru Penguindrum
 * Medaka Box Wiki: Medaka Box.
 * Mermaid Melody Pichi Pichi Pitch Wiki: Mermaid Melody Pichi Pichi Pitch. Still under progress.
 * Nanohawiki: Magical Girl Lyrical Nanoha (in Japanese).
 * Magical Girl Lyrical Nanoha Wiki: Now in English, for all your befriending needs.
 * Narutopedia: The Naruto wiki.
 * Negima! Wiki: Wiki for all iterations of Mahou Sensei Negima.
 * Nichijou Wiki: Wiki for Nichijou.
 * One Piece Encyclopedia: One Piece.
 * Panty and Stocking with Garterbelt Wiki: Panty and Stocking With Garterbelt.
 * Pretty Cure Wiki: Pretty Cure.
 * Pretty Cure Fan-Series Wiki: Has a list of and information on virtually every single fan-series there is, both published and in-development.
 * Prince of Tennis Wiki: The Prince of Tennis.
 * Project WikiMoon: Sailor Moon.
 * Puella Magi Wiki: Puella Magi Madoka Magica and spin offs.
 * Ranma Wiki: Ranma ½.
 * Ranma ½ Fan Fiction Wiki: Ranma ½ Fan Fiction.
 * Ranma Hentai Wiki: Wiki for hentai about Ranma ½.
 * Read or Die Wiki: Read or Die and R.O.D the TV.
 * Satoshi Kon Index: The works of Satoshi Kon.
 * So Ra No Wo To Wiki: A So Ra No Wo To wiki. It even has its own trailer.
 * Soul Eater Wiki: Soul Eater.
 * Strike Witches wiki: Strike Witches.
 * Toaru Majutsu no Index Wiki: A Certain Magical Index and A Certain Scientific Railgun.
 * Tokyo Mew Mew: Tokyo Mew Mew.
 * Tower Of God: Tower of God
 * To The Sky: Last Exile.
 * Umineko no Naku Koro Ni Wiki: Umineko no Naku Koro ni.
 * Yu-Gi-Oh wiki: Yu-Gi-Oh!.
 * There is also WikiFic.
 * Yureka / ID Entity Wiki: Yureka.

Comic Books

 * Archie Comics Wiki Archie Comics.
 * Cerebuswiki: Cerebus.
 * DC Database: The DCU.
 * DC Nation Wiki: The DC Nation Fan Verse keeps a wiki to keep current players and readers abreast of the character divergences, history, and plotlines in their game.
 * The Marvel Database: Marvel Comics.
 * Watchmen Wiki: Watchmen, both the comic and the film.
 * Wonder Woman Wiki: Wonder Woman.

Fan Works

 * Sisterhood of Doom Wiki: For Desperately Seeking Ranma.
 * Averted for Undocumented Features, the fan work which is probably most likely to benefit from one. Primary writer Ben "Gryphon" Hutchins has discouraged a dedicated UF wiki for years on the grounds that one would likely bring attention to the work from intellectual property lawyers, which he would rather avoid.

Films -- Animated

 * Kung Fu Panda Wiki: The Kung Fu Panda franchise.
 * Lilo and Stitch Databank: Lilo and Stitch.
 * Madagascar Wiki: Madagascar
 * Pixar Wiki: A Wiki for all Pixar works.
 * WikiShrek: Shrek.

Films - Live-Action

 * Avatar Wiki: James Cameron's Avatar.
 * Cats and Dogs Wiki: Cats and Dogs
 * Friday the 13th Wiki: For Friday the 13 th films and supplementary material.
 * Inception Wiki: Inception
 * Terminator Wiki: Terminator.
 * TRON Wiki: Tron.
 * Wikizilla: Kaiju, such as Godzilla.
 * Wookieepedia: Star Wars Wiki. With over 82,000 articles, it's enough to earn one a doctorate without going through the franchise.
 * Xenopedia: Alien, Predator, Alien vs. Predator.
 * Ghostbusters wiki: Not only covers the two films, but also the two animated adaptations, the video game and several comics.

Literature

 * The Baroque Cycle Wiki: The Baroque Cycle.
 * Discworld Wiki: Discworld.
 * The Dresden Files: The Dresden Files.
 * Finnegan's Wiki Finnegans Wake.
 * Harry Potter Wiki: The Harry Potter Wiki, so good J. K. Rowling used it.
 * Honorverse Wiki: Honor Harrington.
 * How To Train Your Dragon Wiki: How To Train Your Dragon. Covers both the original books and the Dreamworks adaption.
 * LEPedia: Artemis Fowl.
 * Lone Wolf Wiki: Lone Wolf.
 * One Wiki to Rule Them All: The Lord of the Rings.
 * Tolkien Gateway
 * Prince of Nothing Wiki: Second Apocalypse
 * Redwall Wiki: Redwall.
 * Revelation Space Wiki: the Revelation Space fictive universe
 * Runemarks Wiki: Runemarks
 * Seerowpedia: Animorphs.
 * Skulpedia: Skulduggery Pleasant.
 * Twilight Wiki: Twilight. (The one with the sparkly vampires)
 * Warriors Wiki: Warrior Cats.
 * Wizard of Oz Wiki: Oz books.
 * Survival and Defense Wiki: The Zombie Survival Guide for those who don't have the book, as well as material not in the book.
 * A Wiki of Ice and Fire: A Song of Ice and Fire.
 * Septimus Heap Wiki. Septimus Heap.

Live-Action TV

 * The Babylon Project: Babylon 5.
 * BattlestarWiki: All Battlestar Galactica (both the '70s original and the re-imagining) plus Caprica.
 * Boy Meets Wiki: Boy Meets World.
 * Breaking Bad Wiki: Breaking Bad.
 * Buffyverse Wiki The Buffy Verse.
 * Cold Case Wiki: Cold Case, the show.
 * Deadliest Catch Fan Wiki: Deadliest Catch.
 * Degrassi Wiki: Degrassi
 * Dollhouse Wiki: Dollhouse.
 * Drake And Josh Wiki: Drake and Josh.
 * Everybody Loves Raymond Wiki" Everybody Loves Raymond.
 * Farscape Encyclopedia Project: Farscape.
 * Firefly Wiki: Firefly (contains non-canon extrapolation).
 * Fringepedia: The Fringe Wiki.
 * Grimm Wiki: Grimm
 * Heroes Wiki: Heroes.
 * House Wiki: House.
 * The iCarly wiki: iCarly
 * Kamen Rider Wiki: The Kamen Rider series.
 * Knight Rider Wiki: Knight Rider.
 * Leverage Wiki: Leverage.
 * Lostpedia: Lost.
 * LOST Wikia
 * Memory Alpha: Star Trek.
 * Memory Beta: Star Trek Expanded Universe.
 * Star Trek Expanded Universe: Star Trek Fan Productions. Not to be confused with Memory Beta (above), the wiki for the various novels and comics that make up the literary Star Trek Expanded Universe.
 * Star Trek Online Wiki: Star Trek Online.
 * The Mentalist Wiki: The Mentalist.
 * The Morphing Grid: Despite its name and URL, it covers Super Sentai as well as the Power Rangers franchise.
 * Rangerwiki: Another Power Rangers wiki.
 * Muppet Wiki: The Muppets, Sesame Street, Fraggle Rock and other Jim Henson projects.
 * Henson Alternative Wiki: All Jim Henson Company stuff aimed for more mature audiences (Puppet Up, Late Night Liars, etc.)
 * The Murder, She Wrote Wiki: Murder, She Wrote.
 * Our Gang Wikia Wiki: The Little Rascals.
 * The Outer Limits Wiki: The Outer Limits.
 * Scrubs Wiki: Scrubs.
 * Stargate Wiki: Stargate Verse.
 * The Suite Life of Zack and Cody Wiki: The Suite Life of Zack and Cody and The Suite Life On Deck.
 * Super-wiki: Supernatural.
 * Survivor Wiki: Survivor.
 * Tardis Index File: Doctor Who, K 9 And Company, Torchwood, K9, The Sarah Jane Adventures and the Doctor Who Expanded Universe.
 * The Twilight Zone Wiki: The Twilight Zone.
 * U.S. Game Shows Wiki
 * Victorious Wiki: Victorious.
 * West Wing Wiki: The West Wing.
 * Wheel of Fortune History: Wheel of Fortune, of course.
 * Wiki 24: Twenty Four.
 * The Wild Wild West Wiki: The Wild Wild West.
 * Wizards of Waverly Place Wiki: Wizards of Waverly Place.
 * The X-Files Wiki: The X-Files.
 * Zoey 101 Wiki: Zoey 101.

Music

 * The Beatles Wiki: The Beatles.
 * WikiColdplay: Coldplay
 * Gagapedia: Lady Gaga.
 * JoCopedia: The Jonathan Coulton wiki.
 * Linkin Park Wiki: Which is self explanatory.
 * NinWiki: Nine Inch Nails.
 * The Rolling Stones Wiki: The Rolling Stones.
 * This Might Be A Wiki: They Might Be Giants.
 * Vocaloid Wiki Vocaloid

Newspaper Comics

 * Comic Strips Wiki: Newspaper Comics in general. Has only eight articles, though.
 * Garfield Wiki: Garfield.
 * Peanuts Wiki: Peanuts and other works of Charles Schulz.

Tabletop Games

 * 1d4chan: "Traditional games" as seen by 4chan's /tg/.
 * tgchan wiki: Specifically for quests.
 * BattleTechWiki: BattleTech.
 * Chess Wiki: Chess. (As in the board game, not the musical.)
 * Crimson Skies: The Crimson Skies wiki.
 * D&D Wiki: Dungeons & Dragons.
 * Forgotten Realms Wiki: Forgotten Realms setting.
 * Planescape Encyclopedia: Planescape setting.
 * Spelljammer Wiki: Spelljammer.
 * Dragonlance Wiki: Dragonlance setting.
 * Infinity Wiki: Infinity.
 * LEXICANUM: Warhammer Fantasy Battle and Warhammer 40,000.
 * Magi-Nation Wiki: Magi Nation. Also covers the GBC game and TV Series.
 * MTGSalvation Wiki: Magic the Gathering wiki. Contains information about both the game and the story.
 * Piecepack Wiki: Games for the piecepack, a public-domain board game system created in 2000.
 * Sensei's Library: Encyclopedic wiki devoted to the ancient game of Go.
 * [(unofficial) Traveller Wiki: [[Traveller]]
 * Weiss Schwarz: The anime card game Weiss Schwarz.
 * The (Unofficial) White Wolf Wiki: The White Wolf Wiki. (Including Old World of Darkness, New World of Darkness, Exalted, Scion, Trinity Universe, and various Sword and Sorcery games.)
 * The Official White Wolf Wiki: Covers all of the above White Wolf games.
 * Official Exalted Wiki
 * Unofficial Exalted Wiki
 * World of Darkness Wiki: Old World of Darkness and New World of Darkness.
 * World of Darkness WikiForge: A collection of fan-made material.
 * Lycee Wiki: Visual-novels-based card game, Lycee. Despite the notoriety of its source material, the wiki (and the TCG itself) is Safe For Work.

Toys

 * American Girl Dolls Wiki: American Girls Collection.
 * Beyblade Wiki: Beyblade
 * BionicleSector01: LEGO's Bionicle toyline.
 * Boglins Wiki: For the old Boglins monster puppets, and in definite need of some Wiki Magic
 * Brickipedia: LEGO in general.
 * Dino Riders Wiki: The Dino Riders wiki. Definitely needs some Wiki Magic, considering it only has 7 pages.
 * Wiki Grayskull: He-Man and the Masters of the Universe
 * Joepedia: The G.I. Joe wiki. Sadly not as fun as the Transformers wiki.
 * The Micronauts Wiki: For Micronauts and its related Microman line. Is in desparate need of some, you guessed it, Wiki Magic. I have no idea why toy-related wikis are so prone to needing it, but that's how it is.
 * Monster In My Pocket Wiki: For all incarnations of the old Monster in my Pocket figurines from the early 90s.
 * Nerf Wiki: Nerf and Nerf-related accessories
 * TFWiki.net: The Transformers Wiki.
 * Zoids Wiki: The Zoids Wiki, both for the anime adaptations and the toys they're based off of.

Video Games

 * (dot).hack Wiki: Wiki for .hack games, anime, manga, novels and related media.
 * Ace Attorney Wiki: Ace Attorney series.
 * Ace Combat Wiki: Dedicated to the Ace Combat video game series.
 * ADOM Wiki: The Ancient Domains of Mystery Roguelike.
 * Agarest Wiki: Agarest Senki.
 * Alien Swarm Wiki: For the Alien Swarm game.
 * Aselia: The Tales (series).
 * The Assassin's Creed Wiki: Assassin's Creed.
 * Asura's Wrath Wiki: Asura's Wrath
 * Amnesia: The Dark Descent Wiki: Amnesia the Dark Descent.
 * Bandipedia: Crash Bandicoot series.
 * Battlefield: The Battlefield series
 * Bayonetta Wiki: Bayonetta.
 * Bioshock Wiki: BioShock (series).
 * FanFuturistics: BioShock (series) fanon.
 * Blood Wiki: Blood series, as well as Shogo: Mobile Armor Division.
 * Borderlands Wiki: Borderlands.
 * Bulbapedia: Pokémon.
 * Encyclopædiæ Pokémonis: A network founded by Bulbapedia to establish Pokémon wikis in other languages. Currently at 8, featuring English, German, Japanese, Polish, French, Portuguese, Spanish and Italian versions.
 * Pokémon Wiki, formerly known as the Pokémon Encyclopedia: Another wiki about Pokémon and established rival to Bulbapedia, using Wikia instead of Mediawiki. Much less organized than Bulbapedia and still under construction.
 * Bully Wiki: Bully.
 * Caduceus Database: The Trauma Center wiki. Needs some Wiki Magic.
 * Call of Duty Wiki: The Call of Duty series.
 * Castlevania Wiki: Castlevania.
 * Castlevania Fan wiki: Fanon version.
 * The Codex of Editable Wisdom: The Ultima series.
 * Combine Overwiki: Half-Life and Portal.
 * Valve PotatoFoolsDay ARG Wiki: Valve's April 2011 Portal 2 Alternate Reality Game.
 * Command & Conquer Wiki: Command & Conquer.
 * Counter-Strike Counter-Strike.
 * Crawl Wiki: Dungeon Crawl Stone Soup.
 * Creatures Wiki: Creatures life sim games and fan Game Mods.
 * A Dance With Rogues Wiki: A wiki for the Neverwinter Nights Game Mod A Dance With Rogues.
 * Dead Island Wiki: Dead Island
 * Dead Rising Wiki Dead Rising, moved off Wikia in December and is now independent.
 * Diablo Wiki: The Diablo series.
 * And another one.
 * Disgaea: Disgaea.
 * Donkey Kong Wiki Donkey Kong.
 * The Doom Wiki: Doom.
 * The ZDoom Wiki: Wiki of the ZDoom limit-removing port. Mainly a reference for modders.
 * The Doom Roguelike Wiki: Doom the Roguelike.
 * Dragon Age Wiki: Wiki for the Dragon Age franchise.
 * Dragon Quest Wiki: Wiki for the Dragon Quest series.
 * Dream of Mirror Online Wiki: for the Aeria Games MMORPG Dream of Mirror Online.
 * Dwarf Fortress Wiki: Dwarf Fortress.
 * Earthbound Wiki: EarthBound, Mother 3, and MOTHER 1.
 * WikiBound: Non-wikia.
 * Earthworm Jim Wiki: Earthworm Jim. Mostly about the video game, but information about the animated series will be added eventually.
 * Encyclopedia Ermarian: Exile/Avernum.
 * Etrian Odyssey Wiki: Etrian Odyssey. Could use some Wiki Magic.
 * EVElopedia: CCP's official wiki for EVE Online.
 * There are also quite a few unofficial wikis, which tend to offer more detailed information in certain areas due to being older.
 * Everquest 2 Wiki: EverQuest 2 (but not EverQuest 1).
 * Fantendo: Nintendo Fanon Wiki.
 * FarmVille Wiki: FarmVille.
 * Fig Hunter Wiki: MARDEK, as well as other games by the same author.
 * The Final Fantasy Wiki: Final Fantasy.
 * Dissidpedia: Dissidia Final Fantasy.
 * FFXIclopedia: Final Fantasy XI.
 * Eorzeapedia: Final Fantasy XIV.
 * Fire Emblem Wiki: Fire Emblem franchise.
 * Fire Emblem Wiki: Non-Wikia version
 * Forbidden Siren Wiki: Siren.
 * Fossil Fighters Wiki: For the Fossil Fighters franchise.
 * Gaiapedia: Gaia Online.
 * Gearspedia: The Gears of War Wiki.
 * Golden Sun Universe: The Golden Sun Wiki.
 * Gotcha Force Wiki: The Gotcha Force Wiki.
 * GTA Wiki: The Grand Theft Auto Wiki
 * Grand Theft Wiki: The non-Wikia Grand Theft Auto Wiki
 * Guild Wars Wiki: The official Guild Wars wiki.
 * GuildWiki: The unofficial Guild Wars wiki.
 * GuildWars@Wikia: The spinoff of the unofficial Guild Wars wiki.
 * PvXWiki: Spinoff of GuildWiki for cataloguing character builds.
 * PvX@Wikia: Spinoff of the Spinoff. Once a wiki at Wikia, always a wiki at Wikia.
 * There are several wikis cataloguing the Halo series:
 * Halopedia, a wiki covering the whole series.
 * Halo Nation, another wiki covering the whole series.
 * Halowiki.net for Halo 3's multiplayer.
 * Reach Wiki for Halo: Reach information.
 * The Halo: Reach Stats API Wiki, which advises developers on how to retrieve and use Halo: Reach statistics information.
 * Gruntipedia for Halo-related comedy.
 * The Happy Wheels wikia
 * Hard Drop Wiki: Tetris.
 * Humongous Entertainment Games Wiki: Although still under construction, it covers nearly all of Humongous Entertainment's games.
 * The Wiki for Hyperdimension Neptunia, or Nepperpedia, if you will.
 * Icaruspedia: Kid Icarus.
 * Inazuma Eleven Wiki: The Inazuma Eleven wiki.
 * iNiS Wiki: A wiki for the games made by iNiS, including Elite Beat Agents, Osu! Tatakae! Ouendan, and Gitaroo Man. Unfortunately, it's hardly been developed at all.
 * Insaniquarium Wiki Insaniquarium. Still developing.
 * INWiki: For Imperium Nova. (Yes, even incredibly geeky browser-based games can have extensive wikis!)
 * Jak and Daxter Wiki: Jak and Daxter series.
 * Kingdom Hearts Wiki: Kingdom Hearts.
 * Kingdom Hearts Wiki: Wikia alternative.
 * The Kingdom Of Loathing Wiki: Kingdom of Loathing.
 * King's Quest Omnipedia: King's Quest.
 * Kya: Dark Lineage Wikia: Kya Dark Lineage
 * La.MuLANA Wiki: Has a helpful La-Mulana Starter Guide, along with field maps and walkthroughs for those inevitable Guide Dang It moments.
 * The Liandri Archives: A wiki about the Unreal series of games.
 * LOTLWiki: A wiki for Limbo of the Lost.
 * LSD: Dream Emulator Wiki: LSD Dream Emulator
 * Lylat Wiki: Star FOX Wiki.
 * Mabinogi World, Mabinogi
 * Marathon Wiki: Marathon Trilogy wiki.
 * The Mass Effect Wiki: Mass Effect.
 * Master of Magic Wiki: Master of Magic
 * Mega Man Knowledge Base: Mega Man.
 * Metal Gear Wiki: Metal Gear.
 * Metroid Wiki: Metroid.
 * Wikitroid: The wikia one.
 * Minecraft Wiki: Minecraft.
 * MYSTlore: "A wiki for all things Myst, D'ni, and Uru."
 * NethackWiki: The Nethack wiki.
 * Nexus War Wiki: The wiki for the MMORPG Nexus War.
 * Nintendo Independent Wiki Alliance (NIWA): Not a wiki (though they do intend to put one on the hub site eventually), but an independent network of them. Founded by Bulbapedia, Zelda Wiki, and Super Mario Wiki as a backlash against Wikia, as laid out in the NIWA manifesto. Currently comprised of 18 wikis, including the above three.
 * Nookipedia Animal Crossing.
 * Okami World Wiki: Okami.
 * Paradox Wiki: Red Alert 3 Paradox.
 * Paragonwiki: City of Heroes.
 * Perfect Wiki: Perfect Dark.
 * Pikipedia: Pikmin.
 * Pikipedia: Non-Wikia version.
 * Pikmin Fanon: A fanon edition.
 * Plants vs. Zombies Wiki: Plants vs. Zombies.
 * Platina: Ar tonelico.
 * Primal Wiki: For the tiny following of the 2003 PlayStation 2 exclusive game Primal.
 * Professor Layton Wiki: Professor Layton.
 * Princess Maker Wiki: A wiki about Princess Maker.
 * Psi Ops wiki Psi Ops
 * Psycho-pedia: Psychonauts Wiki, the Psycho-pedia at Double Fine.
 * Ratchet & Clank Wiki: Ratchet and Clank.
 * RayWiki: Rayman.
 * Resident Evil: Resident Evil.
 * Gory Storm: Fanon version.
 * Recettear Wiki: Recettear.
 * Red Dead Wiki: Red Dead Revolver and Red Dead Redemption.
 * Rosenkreuzstilette Wiki: Wiki for the doujin game series of the same name.
 * Rune Factory Wikia: Rune Factory
 * RuneScape wiki: RuneScape.
 * Dark Runescape Wiki: Darker aspects of Runescape.
 * Ryzom wiki: Ryzom.
 * Sam & Max Wiki: Sam and Max Freelance Police.
 * Scribblenauts: Scribblenauts.
 * The Secret World Wiki (TSWW): The Secret World.
 * Shadow Hearts: Shadow Hearts and Koudelka.
 * Shin Megami Tensei Wiki: Shin Megami Tensei.
 * Shiren the Wander Wiki: The Super Famicom and Nintendo DS game MysteryDungeon: Shiren the Wanderer.
 * Shoryuken: A compendium for strategies for all kinds of Fighting Games.
 * Silent Hill wiki: Silent Hill.
 * SimsWiki: The Sims 2.
 * The Sims Wiki: The Wikia version of Sims Wiki. (The other one being operated by Mod The Sims.)
 * The Sims Fanon Wiki: For all Fanon and other derivative works players create.
 * Smash Wiki: Super Smash Bros..
 * SmashWikia: Wikia alternative.
 * SMWiki: Super Mario World ROM hacking
 * SNK Wiki: SNK.
 * Sonic News Network: Sonic the Hedgehog.
 * Sonic Retro: Another Sonic wiki, primarily based around research, hacking and archiving but still with its fair share of universe-related articles.
 * Mobius Encyclopedia: The Archie Comics continuity.
 * Soulcalibur wiki: Soul Series.
 * Space Quest Omnipedia: Space Quest.
 * Speedrunwiki for advice on speedrunning and time attacking strategies in numerous games, primarily GoldenEye, Perfect Dark, Time Splitters 2, and the Mario Kart and Legend of Zelda series.
 * Spelunky Wiki: Spelunky.
 * Spiral Knights Wiki: Spiral Knights
 * SporeWiki: Spore.
 * The S.T.A.L.K.E.R. Wiki: STALKER.
 * Starcraft Wiki: StarCraft.
 * Liquipedia: Programming, tactics and strategy in Starcraft.
 * Liquipedia II: Programming, tactics and strategy in Starcraft II.
 * Starfy Wiki: The Legendary Starfy.
 * StrategyWiki: Collaborative video game strategy guides and walkthroughs (on Jan 2016, 5544 games, of which 708 in a completed state, according to itself).
 * Street Fighter Wiki: Street Fighter
 * Suikopedia: Suikoden.
 * Super Mario Wiki: Super Mario Bros.
 * Super Robot Wars Wiki: Super Robot Wars.
 * Team Fortress 2 Wiki: Team Fortress 2. As official a wiki can get, due to being hosted by Valve themselves.
 * Old Team Fortress 2 wiki before Valve officialised it is here.
 * Tekkenpedia: Tekken
 * TibiaWiki(a): Tibia.
 * Timeshift Wiki TimeShift
 * Touhou Wiki: Touhou.
 * Immaterial and Missing Power and Scarlet Weather Rhapsody/Hisoutensoku Gameplay Wikis.
 * Yukkuri Wiki: Yukkuri, a Memetic Mutation based on Touhou.
 * UESPWiki: The Elder Scrolls.
 * UFOPaedia: X-COM series.
 * The UFO: AI Wiki: UFO Alien Invasion.
 * The Ultronomicon: Star Control II/Ur-Quan Masters wiki.
 * The Urban Dead Wiki: Urban Dead.
 * Valkyrie Profile Wiki: Valkyrie Profile.
 * Vindictus Wiki, Vindictus
 * The Vault: Fallout.
 * Viewtiful Joe World Cinema: Viewtiful Joe.
 * /v/'s Recommended Games Wiki: Exactly What It Says on the Tin.
 * Wars Wiki: Nintendo Wars franchise (Advance Wars, Battalion Wars, Game Boy Wars, Famicom Wars and Super Famicom Wars).
 * Wesnoth wiki: Battle for Wesnoth.
 * WiKirby: Kirby.
 * The Kirby Wiki: Same idea, different makers.
 * The Witcher: Both the novels and the game, The Witcher.
 * The World Ends With You Wiki: The World Ends With You.
 * Wowpedia: Official World of Warcraft wiki.
 * WowWiki - Less official wiki.
 * Wowhead - Wiki based mainly around guides to quests. Each quest can be discussed with questions, tips, and comments regarding bugs.
 * The Xenosaga Wiki: Xenosaga.
 * Yume Nikki Wiki: Yume Nikki
 * Zelda Wiki: The Legend of Zelda.
 * Zeldapedia. Same idea, different people.
 * zOMG Wiki: zOMG!.

Web Comics

 * Axe Cop Wiki: Axe Cop.
 * Bad Webcomics Wiki: Dedicated to discussing why webcomics deserve to die and are totally lame.
 * BiblePedia, BIBLE
 * Collar 6 Wiki: Collar 6 the webcomic.
 * Comixpedia: Web Comics in general.
 * CWCki: The encyclopedia of Christian Weston Chandler's anti-fans.
 * The Department of Almost Certainly True History: Girl Genius.
 * DMFA Wiku: Dan and Mabs Furry Adventures.
 * ErfWiki: Erfworld.
 * GPF: The Wiki: General Protection Fault. (Note: Write access is limited and requires approval.)
 * Gunnerkrigg Court Wiki: Gunnerkrigg Court.
 * Heretic Knowledge Vault: Errant Story.
 * Jack Wiki: Jack.
 * The Meekipedia: The Meek.
 * Misfile Wiki: Misfile.
 * MS Paint Adventures Wiki: MS Paint Adventures.
 * Sweet Bro and Hella Jeff Wiki: Sweet Bro and Hella Jeff
 * The forum adventures wiki has one too.
 * Niftypedia: Sluggy Freelance wiki.
 * Ninja-Theatre.com: Sinfest
 * Order of the Stick Wiki: The Order of the Stick.
 * The Orthorbbae Library: Drowtales
 * Ovalkwiki: The official Schlock Mercenary wiki.
 * And Schlock Mercenary Wiki, the Wikia version.
 * Rhapsodies Wiki: Rhapsodies.
 * Sardapedia: Eight Bit Theater.
 * Shiveapedia: El Goonish Shive.
 * Skin Deep Wiki Skin Deep
 * Survivor Fan Characters Wiki: Survivor Fan Characters.
 * Templar, AZ Wiki: Templar, Arizona.
 * Unwinder's Tall Comics Fan Wiki: Unwinder's Tall Comics.
 * Walkypedia: The Walkyverse.
 * Wikidrug: Ansem Retort.
 * WikiTokyo: Megatokyo.

Web Original

 * Abridged Series Wiki: A wiki for all the Abridged Series out there.
 * ACMSES Wiki: The Anti Cliche and Mary Sue Elimination Society.
 * All The Tropes: A Wiki for storytelling tropes occasionally given to referring to itself.
 * TV Tropes: Another Wiki with the same goals, and the one that the above Wiki spun off from.
 * Tropes Mirror Wiki: Articles that would be otherwise be Locked Pages or examples cleared are sent there. Run by and has contributors from All The Tropes, so they are effectively a Wikia based alternative of this wiki.
 * Fetish Fuel Wiki: Where all of the Fetish Fuel examples formerly on TV Tropes were moved to.
 * Troper Tales Wiki: Where all of the Troper Tales examples formerly on TV Tropes were moved to.
 * The Butlerverse: The Global Guardians PBEM Universe.
 * 101 Wiki: For Channel 101.
 * Channel Awesome Wiki: For Channel Awesome and all affiliated sites (such as That Guy With The Glasses, The Spoony Experiment, Atop the Fourth Wall, and so on.)
 * Chewiki: YouTube Poop
 * Darwin's Soldiers Wiki: Darwin's Soldiers.
 * Encyclopedia Dramatica (the All-Troll Wiki): Laughing at same. Resurrected after the original wiki was Unpersoned.
 * Fandom Wank wiki: Internet drama.
 * Fenwiki: The "encyclopedia"/Series Bible behind (and a partial story archive for) Fenspace
 * Freedom City Play By Post: The largest and longest-running Mutants and Masterminds RPG on the net.
 * GameFAQs boards:
 * Contests
 * Current Events
 * Poll of the Day
 * The Gungan Council Wiki: The Gungan Council
 * Happy Tree Friends Wiki: Happy Tree Friends.
 * Hitler Parody Wiki. Remember that Gag Sub Downfall meme of Hitler ranting? This is the wiki for it.
 * Homestar Runner Wiki: Homestar Runner. Used by the creators themselves.
 * ITM Wiki: A wiki for a homebrew RPG played almost exclusively in the hometown of its local creator. It has rules to play the game on your own. Also has a webcomic planned, according to the wiki.
 * Jadusable wiki: The Ben Drowned ARG.
 * lgpedia: The Breeniverse.
 * Kumikyoku Wiki A wiki for Nico Nico Douga medleys(kumikyokus). Contains lists of songs used.
 * LoadingReadyWiki: The Loading Ready Run wiki.
 * LURKMORE: Memetic Mutation and 4chan wiki. Like Encyclopedia Dramatica, but friendlier.
 * MeatballWiki: Online communities (sorta of an meta-wiki). One of the oldest wikis.
 * NeoDex: The Neopets wiki.
 * NSWiki: The NationStates wiki.
 * OS-Tan Collections Wiki: OS-Tans.
 * PPC Wiki: Protectors of the Plot Continuum.
 * Red vs Blue Wiki: Red vs. Blue.
 * The SCP Foundation: SCP Foundation; a case where the wiki is the work rather than about the work.
 * Shadow Unit Wiki: Shadow Unit.
 * Stupid Mario Bros. Wiki. Stupid Mario Brothers.
 * Survival of the Fittest Wiki: Survival of the Fittest.
 * The Official TalkRadar Wiki: Talkradar.
 * True Capitalist Wiki: True Capitalist.
 * Wiki: The original wiki.
 * Wikigrounds: The Newgrounds wiki.
 * Wikiindex: A wiki about... wikis!
 * Wikipedia
 * See also the other Wikimedia Foundation projects.
 * Once Wikipedia decided that their Bad Jokes and Other Deleted Nonsense page was counterproductive... guess it.
 * Zero Punctuation: Zero Punctuation.

Western Animation

 * 6teen Wiki: 6teen.
 * Adventure Time With Finn and Jake Wiki: Adventure Time.
 * Aladdin Wiki: Aladdin, the sequels and the series.
 * The Amazing World Of Gumball Wiki: The Amazing World of Gumball.
 * Animaniacs Wiki: Animaniacs.
 * Archer Wiki: Archer
 * Avatar Wiki: Avatar: The Last Airbender and The Legend of Korra.
 * Batman: The Brave And The Bold Wiki: Batman the Brave And The Bold
 * Ben 10 Planet: Ben 10 and its spinoffs.
 * Cartoon Network Wiki: Cartoon Network shows, both animated and live action.
 * Captain Planet and the Planeteers Wiki: The wiki for Captain Planet and the Planeteers.
 * The Centurions Wiki: Centurions.
 * Chowderpedia (aka Chowder Fan Club): Chowder.
 * The Cleveland Show Wiki: The Cleveland Show.
 * Courage the Cowardly Dog Wiki: Courage the Cowardly Dog.
 * Criptapedea The Cryptid Wiki: The Secret Saturdays. Don't expect much from it; as of 23 September 2011, it has only four articles.
 * Danny Phantom Wiki: Danny Phantom.
 * Daria Wiki: Daria.
 * The competing Wikia wiki.
 * Darkwing Duck Wiki: Darkwing Duck.
 * DC Animated Universe Wiki: The DCAU.
 * The Disney Wiki: Disney
 * Disney's Hercules Wiki: |Hercules and the series.
 * Drawn Together Wiki: Drawn Together.
 * Ed, Edd N' Eddy wiki: Ed, Edd 'n' Eddy wiki.
 * Exosquad Wiki: Exo Squad.
 * The Fairly Oddparents Wiki: The Fairly OddParents
 * Family Guy Wiki: Family Guy.
 * Filmation Ghostbusters Wiki: Filmations Ghostbusters.
 * Flapjack Wiki Harbor: The Marvelous Misadventures of Flapjack.
 * Futurama Wiki: The Futurama Wiki.
 * The Infosphere, the Futurama Wiki: An alternate Wiki. It also has a link to this wiki, in the Lampshade Hanging section.
 * GargWiki: Gargoyles.
 * Generator Rex Wiki: Generator Rex.
 * The Grim Adventures of Billy and Mandy Wiki: The Grim Adventures of Billy and Mandy.
 * Hanna-Barbera Wiki: Hanna-Barbera cartoons.
 * Hey Arnold Wiki: Hey Arnold!.
 * Imagination Companions: Fosters Home for Imaginary Friends.
 * The Invader Zim Wiki: For Invader Zim. Is not the best of wikis, and could use some help, but is still very informative.
 * Jimmy Neutron Wiki: The Adventures of Jimmy Neutron.
 * Joepedia G.I. Joe.
 * Jonny Quest Database Wiki: Jonny Quest.
 * Kim Possible Wiki: Kim Possible.
 * King Of the Hill Wiki: King of the Hill.
 * KND Code Module: Codename: Kids Next Door.
 * Lilo and Stitch databank: Liloand Stitch, the sequels and Lilo & Stitch: The Series.
 * Looney City Citizens: Looney Tunes and related projects, such as Tiny Toon Adventures and Animaniacs.
 * The Looney Tunes Show Wiki: The Looney Tunes Show.
 * Warner Bros. Animated Universe Wiki: Looney Tunes and related spin-offs (Tiny Toon Adventures, Animaniacs, Histeria!, etc.)
 * My Little Pony Wiki: My Little Pony (the original)
 * My Little Wiki: Though it's more so related to the toys.
 * My Little Pony: Friendship Is Magic wiki: My Little Pony: Friendship Is Magic.
 * Fallout: Equestria Wiki: Fallout Equestria.
 * Nickipedia: Nickelodeon shows, both animated and live action, from the 1990s on.
 * Phineas and Ferb Wiki: Phineas and Ferb.
 * Pooh Wiki: The Wiki for all things Winnie the Pooh.
 * The Raccoons Wiki: The Raccoons.
 * Rangerwiki: Chip 'n Dale Rescue Rangers.
 * Recess Wiki: Recess (Needs more love, please help!)
 * Regular Show Wiki: Regular Show.
 * Robot Chicken Wiki: Robot Chicken.
 * Scoobypedia: Scooby Doo.
 * SilverHawks Wiki: Silverhawks.
 * South Park Wiki: South Park.
 * SpongePedia: SpongeBob SquarePants.
 * Superfriends Wiki: Covers the various Superfriends series as well as almost every DC animated show (as well as a few live-action shows) pre-DCAU.
 * The SWAT Kats Encyclopedia: Swat Kats.
 * Tackipedia: Richard Williams.
 * Teen Titans Wiki: Teen Titans
 * ThunderCats Wiki: Thundercats and Thundercats 2011.
 * Tiny Toon Adventures Wiki: Tiny Toon Adventures.
 * Titan Maximum Wiki: Titan Maximum.
 * TMNTPedia: Teenage Mutant Ninja Turtles.
 * Total Drama Wiki: Total Drama Island and its spinoffs.
 * T.U.F.F. Puppy Wiki: Tuff Puppy
 * Ugly Americans Wiki: Ugly Americans.
 * The Venture Brothers Wiki: The Venture Brothers
 * Wiki Grayskull: He-Man and the Masters of the Universe and She Ra Princess of Power.
 * Wikisimpsons: The Simpsons.
 * Xiaolin Showdown Wiki: Xiaolin Showdown.

Real Life
""It was big and affected almost every nation in the world. Lots of people were poor.""
 * The 1930s Wiki: A wiki about the Dirty Thirties.


 * Armeniapedia: The Armenia Wiki.
 * Ballotpedia: USA referendums and ballot initiatives.
 * Blightynet: The United Kingdom.
 * Boobpedia: Exactly what it sounds like. NSFW, obviously enough.
 * Cactopedia: The encyclopedia for lovers of cacti everywhere.
 * Candy Wiki: A wiki about candy and sweets of all kinds. Sadly, it seems to have been abandoned.
 * Chickipedia: The only intelligent commonly known repository of information to refer to women as "Chicks"; or, if not the only one, certainly the best.
 * Closing Logos Group Wiki: Closing logos.
 * Conservapedia: An alternative for those who think The Other Wiki has a left-wing bias.
 * Liberapedia: A wiki with an actual left-wing bias (Played for Laughs).
 * Creation Wiki: Wikipedia alternative for Creationists.
 * Dickipedia: The wiki of dicks (Dicks as in bad people, not as in male genitalia). Cannot actually be edited.
 * Encyclopedia Titanica: The RMS Titanic Wiki.
 * Fort Wiki: Historic military forts in the United States and Canada.
 * Gas Mask And Respirator Wiki: Gas masks and respirators, for your unnerving viewing pleasure!
 * Intact Wiki: The anti-circumcision wiki.
 * Less Wrong: A wiki on the subject of Rationality, Transhumanism and The Singularity.
 * Metapedia: The wiki for neo-Nazis.
 * Microbe Wiki: On microbes and microbiology.
 * MobileRead Wiki: Of e-books and ways to read them.
 * NFL Wiki: The wiki for the National Football League.
 * Nudist Wiki
 * OpenStreetMap: Editable map of the Real World.
 * Pet Diabetes: A wiki for owners of diabetic pets. Yes, really narrow foci.
 * Pop-Tarts Wiki: In case you were left without TV to catch the conclusion of the latest Pop-Tarts commercial, or are wondering why your favorite flavor was discontinued.
 * RationalWiki: For those who like to mock pseudoscience, fundamentalism, and Conservapedia.
 * SubtiWiki: A wiki about Bacillus subtilis. Yes, a wiki dedicated to a single species of bacteria.
 * T-Vox: Transsexualism wiki.
 * wikiFeet: Feet (of female celebrities).
 * WikiFur: Furry Fandom.
 * Wikipole: A pole-dancing wiki. Many images of moves are animated. The site was created by a woman and it's actually pretty tasteful and informative.
 * Wipipedia: BDSM.
 * Wookieepedia: The hirsute encyclopedia "by and for contemporary Wookiees".