Heaven

Heaven: Dying wish.
Hell: Dead certainty.

—Thorax, 9 Chickweed Lane

The problem lies in Heaven being the pinnacle of perfection, the ultimate reward, so most authors and filmmakers end up feeling not quite up to the task of portraying it (not to mention, one person's heaven is another person's Hell). The easy way out is to use Fluffy Cloud Heaven, The Theme Park Version of Heaven. When that doesn't fit the theme of the setting, the solution is to not show it at all, save perhaps as a tunnel of light for the departed to enter. Or an escalator.

A less simplistic and more dramatic approach is as a "nebula of lights", with each Soul a star, each Angel a comet, and God the Quasar in the center. Another alternative is to use an allegorically benevolent 'purgatory' in the shape of your grandparent's house (complete with apple pie in the oven) or whatever place you were happiest. Even then, those "living" there will inform the new arrival that what they're seeing is a kid-friendly level so that they aren't blown away by the sheer awesome, or because they'll be resurrected shortly and it wouldn't be right for them to feel unhappy on Earth.

Hell, of course, doesn't have this problem and is aaall about the visceral and gory Discretion Shots, so you'll see absolutely Dante-esque hellscapes to put Mordor to shame. The Underworld, being neither particularly pleasant or unpleasant, likewise doesn't have this problem, though if sections of it are equivalent to Heaven, we probably won't see the whole thing.

Frequently, those who've gone into heaven are revealed to have Died Happily Ever After via various means. However, you probably shouldn't try to get them to come back... you wouldn't like the results. See also/Compare A Form You Are Comfortable With.

Not be confused with that film with Cate Blanchett in it.

Examples of Heaven include:

Comic Books

Promethea portrays Heaven using the Tree of Life from the Kaballah. Heaven is also a mirror of the human soul, so in the different spheres of existence a traveler will meet different facets of his or her own personality. Some of the spheres are similar to standard depictions of Heaven (Chesed is a Van Gogh-esque cloudscape, Keter is basically pure light, etc.) while other spheres are... Different.

Fan Works

Heaven is a very literal place in Undocumented Features -- Asgard is an extradimensional but physical location that can be reached if you know where the gateway is, but also is home to the Gods and the dwelling of the souls of those who merited Valhalla.
The Teraverse has (at the very least) the Abrahamic Heaven and Valhalla, as seen in the story Ye Shall Not Die Alone.
How Can It This Be has heaven describes as similar to Mount Olympus, complete with a concert stage for the Spice Girls.

Film

Star Trek: Generations has The Nexus. It's not explicitly Heaven... but it is functionally. It's essentially a Happy Place in physical space that can give you your hearts deepest desire, free of any Aesoptinum fees.
- Except that you probably kill a lot of people getting there. Notably, no one from the Enterprise is shown in the Nexus...only Picard and Guinan (who probably has superpowers, let's be honest).
  - There is no cost per se, you just need to be in a place that intersects with it. Unfortunately, one way to get it to intersect with you is to blow up stars so you can deflect it into your path. (Because that's so much easier than figuring out its path and putting yourself in its way.)
It's a Wonderful Life uses the "nebula of lights" version in the opening, showing three stars flashing as the angels talk in a voice over.
Seen briefly at the end of Ghost as Sam Wheat is welcomed into the afterlife.
Pretty much half of What Dreams May Come is a depiction of Heaven.
The film Gladiator has a scene depicting Elysium, which looks rather like Arcadia. The titular gladiator is met by his wife and young son while a pleasant but ultimately incomprehensibly-lyricked tune runs in the background.
The original Bedazzled uses the Royal Gardens at Kew as the location shot for Heaven.
Very, very thoroughly averted in The Prophecy. After thousands of years of war the rogue angel Gabriel and his faction, and the angels loyal to God led by Michael, who are fighting over letting humans into heaven and humanity's place in God's eyes/favor, things in heaven aren't so pleasant anymore.

Literature

The heaven of Dante's Divine Comedy is the "nebula of lights" version, with radiant souls flocking around in symbolic constellations like a rose, a cross and an eagle—although in illustrations, there's usually some fluffy clouds there as well.
The Five people you meet in Heaven^[context?]
The Great Divorce by C. S. Lewis has people visiting Heaven on a day pass from Hell—neither is quite the stereotypical place.
- C.S. Lewis also has as a nontraditional heaven as part of the Chronicles of Narnia, which looks almost identical to the "normal" world, or rather the "normal" world is almost identical to Heaven; as Professor Digory Kirke puts it in The Last Battle:

"And of course it's different; as different as a real thing is from a shadow or as waking life is from a dream. It's all in Plato, all in Plato: bless me, what do they teach them at these schools!"

What Dreams May Come^[context?]
Oddly enough, despite the general belief of many Christians, The Bible does have fairly detailed descriptions of the Christian heaven from a physical point of view, including dimensions, structures, geographical features, and the normal attire its residents generally wear. What's more, taking the descriptions literally makes more sense than strictly symbolically, which is unusual for John of Patmos's visions.
- In particular, the New Jerusalem, the "capital" of the post-Doomsday Heaven and Earth, is described in Revelation 21-22 as a cubical golden box several thousand miles on a side, its walls supported by foundation stones of precious minerals, twelve gates made from a single (titanically large) pearl each (the original "pearly gates"). Inside is Christ's throne, a golden thoroughfare down which flows a river of the water of life, and ever-bearing Trees of Life.
- Which heaven? The current version, or the finished product, aka "New Earth"? Let's face it; while it may have its moments, our world is at least partially a Crapsack World, even if not to the extent often used for that image -- but according to the beginning of the book, it wasn't meant to be that way. So why not a repaired version that's literally heaven on earth?
In The Lovely Bones, Heaven is unique to each person; he or she is given things they most deeply want (except, of course, to be alive again on Earth). For protagonist Susie Salmon, the setting for her Heaven is the high school she never got to attend.
In Hans Christian Andersen's "The Little Match Girl", the eponymous girl dies, and her dead grandmother carries her soul to Heaven: "They both flew upwards in brightness and joy far above the earth, where there was neither cold nor hunger nor pain, for they were with God."
The Star Trek Novel Verse has quite a few alien takes on heaven. For the Nausicaans, there's Heart of the Sky; for Bolians, the Vein of Mystery; for Trill, Mak'Relle Dur; for Betazoids Great Fire; for Efrosians, Endless Sky; for Xenexians, Kaz'hera (a Warrior Heaven); for Cardassians, the Hall of Memory.
The Culture novels have virtual reality "afterlives". Because a mind can be copied and digitised, it can then be put into a simulation, usually at the point of death. Whilst this means that Heaven (or whatever equivalent exists for each individual alien species) can be made real, it also means that Hell can exist too. And then there are the Sublimed, who may or may not be capable of creating genuinely "real" heavens.
Warrior Cats has StarClan for Clan cats and The Tribe of Endless Hunting for Tribe cats. However, the cats in these heavens can communicate on rare occasions, and it is possible for a cat to belong to both.

Live Action TV

In Angel, after Cordelia ascended to a higher plane, we see her in Heaven next season. It shows her as an angelic floating entity of light floating in a hazy pastel environment. Her first pronouncement? "I'm bored"
This quote from Buffy the Vampire Slayer pretty much sums it up:

Buffy: I was happy. Wherever I ... was ... I was happy. At peace. I knew that everyone I cared about was all right. I knew it. Time ... didn't mean anything ... nothing had form ... but I was still me, you know? And I was warm ... and I was loved ... and I was finished. Complete. I don't understand about theology or dimensions, or ... any of it, really ... but I think I was in heaven.

- Buffy also sings about heaven, and her unexpected return from it, in Once More With Feeling:

Buffy: There was no pain / No fear, no doubt / 'Til they pulled me out / Of heaven. / So that's my refrain: / I live in hell / 'Cause I've been expelled / From heaven. / I think I was in heaven.

Ghost Whisperer.
In Supernatural heaven, you relive your best memories. Actually, this being Supernatural, it's not that great: you spend eternity reliving the same moments, knowing perfectly well they're not real (Dean compares it to the Matrix); unless you have a soulmate, you'll never see any of your loved ones again; and now, apparently, angels can use your soul as a weapon. It is, however, far preferable to hell.
An odd instance of "not quite heaven" that obeys similar rules happens in the Astral diner from the Stargate SG-1 episode "Threads". It's basically the ascended realm boiled down to a level that Daniel's unprepared mind can accept (because he hasn't yet made his final choice whether to ascend or stay mortal).
Dead Like Me never shows Heaven, but does show what the passage there looks like: whatever the deceased most loved to do in life. One guy sees a cliff he once dived off. A girl in the first episode sees a carnival. The Reapers that take the souls can see these images too, but are not allowed to enter them. One Reaper does, halfway through the first season, and completely vanishes. Despite Rube trying to find out what happened to her, it's left entirely unanswered.
The Twilight Zone had an episode written by Earl Hamner where an Appalachian mountain man and his dog died, and the afterlife was just like his everyday world. On a dirt road, a gatekeeper at what was ostensibly Heaven told him no dogs were allowed, so he refused to enter a place that wouldn't take his dog too. Later on, another traveler informs him that was the gate to Hell (and dogs can tell) and Heaven was a way up further.
In the series finale of Lost, all of the main characters enter a bright light that is implied to be heaven.
Star Trek: In addition to the film and literature examples above, there is also the Klingon Warrior Heaven Sto-vo-kor, first mentioned in an episode of Star Trek: The Next Generation.
Red Dwarf makes mention of "Silicon Heaven", which appears to the be afterlife for any device with any amount of computing power, all the way down to pocket calculators. Its actual existence, however, is debatable.

Tabletop RPG

Dungeons and Dragons: several canon and many homebrew campaign settings have their own heavens and hells, often several different ones per setting!
- In a particularly interesting case of "one man's heaven, another man's hell", most Heavens are alignment based, so that there's a Lawful Good and a Chaotic Good heaven. The hells are "heavens of a sort", since they are the Evil part of the spectrum. Lawful Evil hell is even considered relatively nice, all things considered.
  - To clarify, the main problem with going to one of the Lower Planes is that all the other people who went there are evil too, and you start at the bottom of the ladder.
- More notably, the heavens are based on different "concepts" of heaven, from most lawful to most chaotic: Arcadia is all about order and Law and society as a perfectly regimented place, ruled with benevolence and justice. Celestia is all about disciplined and constant self-improvement (symbolized by climbing the mountain, when you reach the top... Well, you you don't come back. Bytopia is about the pleasures of honest living and hard work. Elysium is about calm and restfulness (so much that people have trouble leaving) The Beastlands is all about Ghibli Hills and unspoiled nature a la Rousseau. Arborea is all about swashbuckling and High Adventure, while Ysgard is all about competition and contest.
In Exalted, Heaven is just a enormous city where the top gods live. Ordinary humans have little to no chance of ever getting there, and the Odd Job Gods aren't based there either. The afterlife is the rather crapsacky Underworld, though you might reincarnate. Or be made into soulsteel.
In Nomine‍'‍s Heaven has a whole bunch of different areas (called Cathedrals although only some of them are actually buildings), the dead people can hang out in whichever area suits their fancy, there is an endless party, a library containing not only anything that has ever been written, but some things that somebody only thought (or dreamed!) of writing, a number of different places of worship, including one that always appears to be a perfect site of worship for any observer's religious leanings, etc. And all this is just the lowest level of Heaven. The Upper Heavens are essentially a place of perfect transcendent joy, souls that go there don't come back. Hell is similarly varied, with an area that's like the stereotypes of Las Vegas writ large, an area with lava pits where people are tortured, etc. Most souls don't go to either though, they just reincarnate.
Mage: The Awakening features the Aether, the Supernal Realm associated with the Arcanum of Forces (fire, electricity, gravity, sound, light, etc.) and Prime (the very essence of magic itself). It is a realm of endless, glorious light and limitless power, and it's home to angels, beings of pure energy and unflagging resolve. No souls seem to enter the Aether after death, however; most pass through the Underworld, and the only mortals who visit the Aether are mages who Awaken to the Obrimos path.

Video Games

The 'Farplane', of Final Fantasy X-2.
- A bit of a subversion, as the Farplane isn't really Heaven, it's just a place where pyreflies will form the image of someone who has passed away. The image cannot speak, and doesn't seem to have any emotion or recollection of the person that summoned them. Dead people appear to go to somewhere else, and the pyreflies are what remains of their souls, although the game itself remains vague on the true nature of the Farplane.
Subverted horrifyingly in Bayonetta. Paradiso may look like Fluffy Cloud Heaven, but it's more like the Light-Themed version of Inferno. Note that Hell really is a bad place and that the Angels are Eldritch Abominations. You do the math.
Several in Touhou. The White Jade Tower where Yuyuko and Youmu dwell is a place for virtuous dead (or in Youmu's case, half-dead), while Celestials such as Tenshi lives in a heaven for people chosen by the gods. Eiki implies that there are other good places for good people. The main characters can go to White Jade Tower as much as they like for partying, even if they are neither virtuous nor dead.
Sovngarde from The Elder Scrolls V: Skyrim, Heaven to the Nords, which appears to be something similar to Valhalla.

Web Comics

Heaven in The Order of the Stick is a good allegorical version; at the lowest levels, it's sort of an earthly paradise: "The Tavern of Infinite One-Night Stands," "the Debate Hall Where You're Always Right", and so on. However, eventually people go upward toward true perfect enlightenment once their fleshy urges are sorted out.
In Misfile, it's where the files that tell the universe how to be are kept and the angels hang out. To be honest though, the few glimpses we've seen of it make look more like a backdrop from Star Trek.