The Concept: Based on a forgotten 80s TV show and starring Channing Tatum in a leading role - an actor who had never displayed sufficient comedic chops in any of his earlier movies - 21 Jump Street seemed like it was set up to fail from the very beginning.
Tatum and Jonah Hill looked like a ridiculously mismatched pair, and at this point, the "high-school comedy" had been done to death. This seemed like a minor blip on the radar, at best.
The Movie: But fortunately, 21 Jump Street was a lot smarter than anyone expected.
On the surface, it looked like a dumb, formulaic comedy, but by embracing and often subverting teen movie tropes, Lord & Miller's hilarious script was able to rise above them, packing a wit and sense of self-aware humour that felt refreshing in a market saturated with samey comedy movies.
This was also the movie that turned Channing Tate-yum from a wooden jock into a bonafide leading man - which, ironically, was a transition he made while playing a wooden jock. Smooth.