Calling 21 Jump Street "the best comedy of the year" may seem as premature as it is surprising. And yet, critics say the weekend's big new release is so uproariously smart that it will be hard for any 2012 comedy to top it. Despite being based on a kitschy '80s TV show known more for launching Johnny Depp's career than for producing particularly worthwhile television, the new Jonah Hill and Channing Tatum-led comedy is defying audience expectations. (Watch a trailer below.) The two actors play Schmidt and Jenko, recent police academy graduates who, after an epic on-the-job goofup, are reassigned to work undercover in a high school, where they must infiltrate a drug ring. Here, five reasons critics are lauding 21 Jump Street:

1. The perfect chemistry between Tatum and Hill
From "bromance" to "bromosexuality," a litany of cutesy terms have been employed to describe the platonic bond between male leads in buddy comedies like I Love You, Man and The Other Guys. "What Jonah Hill and Channing Tatum have in 21 Jump Street scrambles, transcends, and explodes all of that," says Wesley Morris at The Boston Globe. The two actors are the film's secret weapon, says Rene Rodriguez at The Miami Herald. Their easy rapport makes it instantly believable that they've been best friends for a decade.

2. Tatum's breakout comedy performance
Channing Tatum is best known as the beefy heartthrob from The Vow, the bland action star of G.I. Joe, and the introspective dancer from the Step Up films. But it turns out that Tatum has a "lunatic twinkle" that brilliantly lends itself to comedy, says Morris. "He knows about 300 ways to play dumb, and this movie lets him try them all." True, says Lisa Schwarzbaum at Entertainment Weekly, the guy's got a "great, I mean great, Dumb Face." This is the kind of breakout "funny, self-aware comic" performance that we haven't seen in years.

3. Its thwarting of low expectations
No one exepcted a hit for this big-screen update of an unflinchingly of-its-time '80s TV show. Channing Tatum has never been funny before, and Jonah Hill is coming off an Oscar nod for serious work in Moneyball. The only movie its co-directors have made is the animated Cloudy with a Chance of Meatballs. So really, the hilarious 21 Jump Street turns "predictability on its head," says Joe Neumaier at New York's Daily News. This could easily have gone the camp route, like the '90s film version of The Brady Bunch, says Morris. But 21 Jump Street is so much smarter than that.

4. The hilariously apt social commentary
The adult characters' return to high school sets up a brilliant running joke about "high school evolution which doubles as a comment on social progress," says Morris. The cool kids in 2012, they learn, are the "hipsters/earth-lovers/P.C. liberals," nailing exactly how "class dynamics have altered since the TV show's run on primetime," says Ben Travers at Pop Matters. Tatum and Hill are a riot as they try to make sense of this, with Tatum's Jenko noting, "I blame Glee."

5. The impressively smart humor
"This is the rare breed of Hollywood studio production that has the brash spirit of an independent picture and the sharp wit of a stand-up comic," says Rodriguez. It's not raunchy just to be shocking, or overly crass and sexual to feign edginess, says Travers. Instead, 21 Jump Street simply relies on smart dialogue and a brilliant concept. The film earns its R-rating, but it's "never crude or mean-spirited or dumb."