I didn't know this going in, but 21 Jump Street is a comic adaptation of an 80's police procedural TV show about cops who go undercover into high schools and colleges because of their youthful appearances. In this 2012 version, best friends Jenko (Tatum) and Schmidt (Hill) are sent into the undercover unit at 21 Jump Street, aka the Aroma of Christ Korean church, with the mission of infiltrating a drug ring that has popped up at a local high school. Jenko is excited to relive his glory days, but soon discovers that the status symbols and hierarchy that put him on top have completely reversed compared to 7 years prior. Now the environmentally-friendly vegans (Franco, Larson) are the cool kids, and Schmidt realizes he may finally get a second chance at high school popularity.
To put it simply, the movie is awesome. It is one of the funniest I've seen recently, on par with the best of Judd Apatow (and in the same raunchy, irreverent style). It pokes fun of endless remakes, of the action comedy genre, and especially of itself. It spends no time on character development and no time on plot progression. Instead it spends 100% of the time on comedy, and it more than pays off in the jokes department. However, it doesn't try to make a point, and therefore it doesn't have the same potential as the best comedies in terms of staying power. But this movie is spectacularly funny, and I cannot recommend it enough.
IMDb link: http://www.imdb.com/title/tt1232829/