Heterosexual Life Partners/Western Animation

"Stan: I don't wanna hang out in the kids' room. I won't know anybody. Randy: Well, it would be good for you to make new friends. You can't just hang out with your buddy Kyle all the time. People will think you guys are, you know, funny."
 * Teen Titans: Beast Boy and Cyborg. Or, alternatively, Cyborg and Robin.
 * Lenny and Carl" from The Simpsons.
 * Pinky and The Brain, though in all fairness, they're forced to live in a cage. They break out a lot, though.
 * Optimus Prime and Bumblebee in Transformers. Bought to mind in particular when Bumblebee drives into Optimus's trailer when in vehicle mode.
 * Darkwing Duck and Launchpad McQuack. Darkwing called Launchpad his "Sidekick", but the dynamic was different. There's even less explanation for his living in DW's civilian house, plus Launchpad didn't even bother with a Secret Identity.
 * Spongebob and Patrick from Spongebob Squarepants.
 * Following the series' return, Stewie in Family Guy seems to have abandoned his plans for world domination just to have more time to hang out with Brian, formerly his arch rival. "Brian & Stewie" even has them admit that they love each other as friends.
 * Mac and Bloo from Foster's Home for Imaginary Friends. Never mind the fact that Bloo is a figment of Mac's imagination... Although, to be fair, most of the supporting cast are figments of the imagination. Back to Mac and Bloo, Mac has made a deal with Mrs. Foster to meet with Bloo everyday. It's even a plot point in some episodes.
 * Ren and Stimpy are a textbook example of the trope Depending on the Writer. In the ill-fated revival series that briefly ran on Spike TV, Ren and Stimpy were actually a gay couple. Word of God says that their status depends on which is funnier for the specific episode, and the extent of Ren's contempt towards Stimpy seems to vary Depending on the Writer. Especially in earlier episodes, they're portrayed as a fairly normal pair of buddies, with little venom coming from Ren. Some episodes of Adult Party Cartoon show their relationship as a borderline type 1 of Vitriolic Best Buds (like "Stimpy's Pregnant"), while others make Ren out to be rather tender and kind-hearted towards Stimpy ("Onwards and Upwards"). It happens in the original series too, though much more subtly ("Rubber Nipple Salesmen" for the first example, "Son of Stimpy" for the second).
 * Stan and Kyle from South Park.

"Kyle: Don't you get it? I don't need you anymore! Stan: I know. I need you."
 * Especially in the Guitar Hero episode.

"Terrance: Wow, Scott really hates us Phillip. Phillip: Yes, perhaps he's homophobic. Terrance: ...But we're not gay, Phillip. Phillip: We're not?!"
 * While not seen on the show much, anymore, Ned and Jimbo qualify.
 * Terrance and Phillip, while we're at it. They were once Mistaken for Gay. By Phillip.

"Cartman: You know, it's funny Kenny. Stan and Kyle have always sorta been two best friends you know, and...Well, I don't know if I ever told you this Kenny, but, um...I always kinda thought you were my best f-f-friend. Don't you worry Kenny. I'm gonna find a cure for you! Everything's gonna be okay."
 * While the show focuses on Stan and Kyle, Cartman and Kenny share this relationship. Particularly evident when Kenny is in the hospital dying of a terminal illness


 * And then there's Ace and Gary, the Ambiguously Gay Duo.
 * An audio commentary from the actors said that they thought the funniest outcome would be to have one of the Duo be gay, but couldn't agree on which one.
 * Norbert and Daggett of The Angry Beavers. Being brothers helps.
 * Daria: While there's never even any subtext of romantic involvement, Daria and Jane otherwise fit this trope, especially the way Daria gets intensely jealous of Jane's boyfriends.
 * The romantics angle is joked about by the show; one of the "Daria Day" marathon host segments features them as husband and wife, and in another host segment with Daria as a nude model, Jane cracks that she can paint Daria's form "from memory".
 * Carl, Jimmy, and sheen from Jimmy Neutron Boy Genius.
 * Swat Kats: Chance Furlong and Jake Clawson spend nearly all their time together, even at the salvage yard garage where they live.
 * My Gym Partner's a Monkey has Adam Lyon and Jake Spidermonkey. One episode even had them paired to take care of an egg in class.
 * Another has Jake publicly crying when Adam is absent for a day.
 * Futurama had Fry and Bender. Bender is also extremely possessive and jealous, and gets angry/weepy when he can't live with Fry, or when spends more time with his girlfriend than Bender in The Movie. Sometimes expanded to Fry, Bender and Leela.
 * The Canadian cartoon Kevin Spencer features the characters of Porn Man and Afro Man, who not only co-star in the adult films they act in, but also share a swinging bachelor pad. There's no Ho Yay between them, though, since they get more than enough action both in their day jobs and at the wild parties they host in their free time.
 * The Platypus Brothers in Taz-Mania. To a lesser extent, Taz and Digeri Dingo since they've known each other since birth and Taz always goes along with Digeri's schemes.
 * Beavis and Butthead (though in This Book Sucks, it's explained that they're ).
 * Ami and Yumi in Hi Hi Puffy AmiYumi are like this. They live in the same dwelling...but it's a tour bus, which they travel the world in, along with their manager Kaz. Though there are times at which they appear to be a little too close not to be doing each other, they have both shown strong interest in men and fought over a male nerd, labeling them as bona-fide Heterosexual Life Partners. (No Bisexuals?)
 * Stan and Koji in Oban Star Racers.
 * Diadoro and Gomez in Combo Ninos.
 * Toot and Puddle, two animated pigs starring in a program by the same name, based on a series of picture books, by the same name. Live together in a small home in the burg of Woodcock Pocket / Pocket Hollow and often travel together.
 * Badger and Mole of Animals of Farthing Wood are inseparable and they often worry about each other when one of them goes missing with Mole being the most emotional about it often bursting into tears, in fact after Mole dies Badger just can't accept the fact he mistakes Mole's son Mossy for him as they look alike and he goes along with it because he was told it would break his heart he remains his companion until Badger passes away of old age.
 * It was different in the books however. Badger never died, but Mossy did. Badger found the body and as such, it's pretty clear that he can't go into denial a second time.
 * Virgil and Richie from Static Shock. Helped along with the fact that it's been admitted that Richie is gay by the animators and in the original comic Rick, who Richie is based on, is gay and there is even an arc where Virgil deals with his feelings on the matter.
 * Barbie and Teresa (and their story colunterparts Liana and Alexa) in Barbie and the Diamond Castle.
 * Chip 'n Dale Rescue Rangers: Chip and Dale.
 * Rocko and Heffer.
 * Fred Flintstone and Barney Rubble are a popular example of this.
 * The Venture Brothers has Henchmen 21 and 24. 21 even lampshades this in a third-season episode, when The Monarch doesn't know who 24 is.
 * "You know whenever you're talking to me, there's another guy with me? That's 24!"
 * The "Jet Boy, Jet Girl" conversation.
 * The Venture Brothers is nothing but Heterosexual Life Partners. Even if you don't count the aforementioned, plus the eponymous characters, you have Brock and Rusty, Pete and Billy, Tim-Tom and Kevin, Watch and Ward, Shore Leave and Mile High. And the creators of the show, who most of the characters are based on in some sense.
 * Mac and Tosh otherwise known as the Goofy Gophers from Looney Tunes they are super polite to each other and agree with what the other says, many people have mistaken them for gay but in several cartoons they have fallen in love with female gopher disguises.
 * Yogi and Boo Boo.
 * Pixie and Dixie.
 * Quick Draw McGraw and Baba Louie.
 * Snooper and Blabber.
 * Hokey Wolf and Ding-A-Ling.
 * Peter Potamus and So-So
 * Breezly and Sneezly
 * ...and a number of others. Let's just say that this trope was a semi, if not regular occurence in Hanna-Barbera's shows.
 * Phineas and Ferb, a pair of inseparable (step)brothers. Also, from the same show, Perry and Doofenshmirtz. (Word of God says they didn't want to give Perry a girlfriend because he's Married to the Job--beating up Doofenshmirtz.)
 * To a lesser extent, Buford and Baljeet, whose bully/nerd relationship is portrayed more like a weird kind of friendship. You could even make an argument for Monogram and Carl, since they're always seen around each other. (Though that's an Unfortunate Implication.)
 * Candace and Stacy also count for this.
 * Skwisgaar Skwigelf and Toki Wartooth from Metalocalypse are a fairly good example of this trope. While they constantly bicker over Toki's role in the band and Skwisgaar is just generally a Jerkass to him in almost all of their interactions, they often choose to hang out with each other exclusively and once in a blue moon they will come to the other's defense (Skwisgaar in "Dethrace", for example). They've also waxed philosophical together about subjects such as family and women (well as philosophical as you can get with this show). Considering that Toki has stolen Skwisgaar's clothes to emulate him in a Dethklok tribute band, offered him a **** in exchange for not getting kicked out of the band, and dated a girl that looked exactly like a female version of Skwisgaar, some fans would argue that Toki is or was actually nursing something of a Tsundere-esque crush on him.
 * It's worth noting that when Toki hangs out with another guitarist in Dethlessons, Skwisgaar's confrontation almost sounds like someone finding their spouse with another partner. And Toki's line "I've always hated you, Skwisgaar" in the first season finale is met with an almost affectionate sounding, "I knows, Toki. I knows." The previous line, in which Skwisgaar's post-mortem plans include hanging out with Toki in Valhalla. Often times they hate each other, but they're also incredibly dependent on each other.
 * Poison Ivy and Harley Quinn in Batman TAS, one of the few villain team ups that is based on friendship, rather than mutual gain. Though the Word of Gay probably strikes out the "heterosexual" part.
 * In Invader Zim, Red and Purple. An unfinished episode reveals they were hanging around each other even before being appointed co-rulers of the Irken Empire. One could also argue Zim and Dib, in a weird, twisted sort of way.
 * Zim and Gir!
 * Or for that matter, Gir and Tacos.
 * Jimmy Two-Shoes and Beezy Heinous.
 * Chris and Chef Hatchet from Total Drama Island.
 * Even more so, Katie and Sadie, who take being "best friends" to a bizarre level. Lindsay and Beth develop a similar but more grounded relationship, especially in TDA.
 * Owen and Noah also become this in TDWT.
 * Russel Hobbes of Gorillaz actually described his best friend Del as his soulmate - he was, since Del's ghost lived in Russel's brain for several years. Russel is the only one of the three living male band members who doesn't have numerous illegitimate offspring, and we've never heard about any women in his life, so, um...
 * Murdoc and 2D show us what happens when Heterosexual Life Partners also happen to have an abusive relationship. Usually this is played for laughs, though 2D's Woobie status has grown in the latest arc. However, considering that Murdoc's strongly hinted to have some Depraved Bisexual tendencies, the heterosexual part is a little open-ended.
 * Peri and Entrèe from Spliced.
 * Fanboy and Chum Chum are two best friends who live together in a water tower with no parents whatsoever. Taken to the extent that the very stability of the fabric of the universe depends on them being together.
 * Bill the duck and Aldo the alligator on Sitting Ducks.
 * Sokka and Zuko from Avatar: The Last Airbender seem to be headed this way, even though they didn't get a whole lot of on-screen interaction. To fanfic!!
 * Arguably, Mai and Ty Lee as well.
 * Aang and Sokka seem to fit this trope.
 * Scooby and Shaggy in Scooby Doo Mystery Inc, to the point that it prevents Shaggy and Velma from having an actual romantic relationship.
 * Thrasher and Blastus in Robotomy.
 * Robin and Kid Flash in Young Justice. They bicker with each other, cockblock each other, and have their own exploding bro-fist. While Batman has told Dick not to reveal his secret identity to his teammates, Word of God says that he did tell Wally.
 * Rocky and Bullwinkle
 * Mordecai and Rigby from Regular Show. "Bros" in the standard definition, as they act like two college roomies.
 * Finn and Jake from Adventure Time, though raised as brothers, and referring to each other as 'brother', are this to a T.
 * In My Little Pony Friendship Is Magic, Rarity and Fluttershy are shown to be closest friends with each other out of the rest of the Mane Six. Rainbow Dash and Pinkie Pie are sometimes shown to be closest friends with each other as well.
 * And to round it all out, we have Twilight Sparkle and Applejack, who often turn to each other for advice or comfort.
 * In Recess, Mikey and Gus seem to be the closest friends with each other out of the main six main characters, and often take each others' sides in conflicts.
 * Same with T.J. and Vince.
 * And to finish off the main six, Spinelli and Gretchen
 * Outside the main six characters, you've got Sam and Dave, the diggers.
 * Mark Lilly and Randall Skeffington in Ugly Americans. Randall has a habit of getting pretty Ho Yay with Mark, much to his discontent.