While all three cartoons are at the cutting edge of the genre, each exudes a singular charm. The biggest on campus is, by no coincidence, the weirdest. Imagine a hallucinogenic “Tom and Jerry” and you have “Ren & Stimpy. " Ren, a scrawny, ornery chihuahua, looks a little like Sammy Davis Jr. and talks a lot like the Frito Bandito. Stimpy, Ren’s significant feline other, is a fat, slow-witted doofus, the Homer Simpson of the cat world. Though this odd couple gets around-from Sherwood Forest to the Crab Nebula, in fact-the cartoon is considerably longer on style than story, and its style is irresistibly whacked. Animator John Kricfalusi (“The New Adventures of Mighty Mouse”) mixes garish colors, a frenzied pace and surreal sight gags to create a uniquely deranged universe; this is pop-art television.

As for the vocal lines, they’re drawn from everywhere. One episode spoofed Hollywood phonies, toy commercials and Kirk Douglas in “Champion” (“We’re not hitchhiking anymore, Stimpy. We’re riding!”) But the show’s favorite target is its own television genre. When Stimpy starts gorging on Saturday-morning cartoons, Ren flips out: “Don’t you know cartoons will ruin your mind? I’m losing all respect for you, YOU BLOATED SACK OF PROTOPLASM!”

Peruse some of “Ren & Stimpy’s” fan mail and the encomium that surfaces most frequently is “twisted.” As in: “Keep up the killer work and twisted scripts.” The letters also reveal that frat rats from Harvard Square to Berkeley are throwing “R&S” viewing parties, everyone wants to start an “R&S” fan club and there’s a rabid demand for “R&S” T shirts, so far inexplicably untapped. Oh, yes, the newest campus putdown is “bloated sack of protoplasm.” No wonder MTV, Nickelodeon’s determinedly hip sister network, recently decided to add the cartoon to its weekend-night lineup. At the opposite “Nicktoon” extreme is “Rugrats,” which looks at life from the perspective of 1-year-olds. The chief rugrat is Tommy Pickles, a boundlessly curious explorer of the world beyond his crib (whose lock he’s learned to pick). This requires the animators, all of whom worked on “The Simpsons,” to skew everything through a baby’s eye, and they do it brilliantly. A toilet bowl looms like a porcelain mountain, a sleepwalking father becomes a robot monster. Unlike kidvid’s standard-issue toddlers, nobody here works overtime to be cute. Tommy and his pals scrawl on walls, trash bathrooms and get into spectacularly messy mush fights. Adults will dig the deft jabs at “thirtysomething” parents reverently flying by the latest child-rearing book (e.g., “What Kids Fear”).

The third show on Nick’s block, called “Doug,” celebrates a painfully ordinary 11-year-old. Dweebish and shy, Doug Funnie often feels left out, especially in his now suburban neighborhood. But his essential sweetness helps him muddle through such trials as a disastrous haircut and his first costume dance, which he attends dressed as a slug. When Doug’s not daydreaming, usually about having a nervous breakdown, he carefully records his life in his diary (“Dear Journal. Me again. Doug”). This is the best written of Nick’s trilogy, right down to its characters’ names: Patty Mayonnaise, the prettiest girl in school; Roger Klotz, a leather-jacketed bully; and Lamar Bone, a prissy assistant principal. Perhaps TV’s most gentle cartoon, “Doug” offers hope that you don’t need an eat-my-shorts attitude to impress the preadolescent audience.

Prime time: The success of “Nicktoons” coincides with the spread of cartoon shows into network prime time. But from the look of things so far, it’s a development that should be arrested. ABC’s Washingtonbased “Capitol Critters,” co-created by Steven Bochco and premiering this week, has about as much political bite as “Alvin and the Chipmunks.” CBS’s heavily heralded “Family Dog” needs more than its teeth sharpened: it came off so badly at a prelaunch screening that it’s been sent back to the shop for an overhaul. Obviously, mold-breaking animators still exist. The trick is to recognize the ones with an original vision and then give them a creative free hand. Both ABC and CBS, by the way, turned down “Ren & Stimpy” before Nickelodeon picked it up. There’s a lesson here even a dumb cat would grasp.