Funniest movie I've seen since "Wedding Crashers". Unlike a lot of recent comedies that seem like SNL skits loosely strung together, "The Hangover" has a complete storyline that actually fits together. One misadventure begets another as three hapless dudes try to find their about-to-be-married bud after a night none of them can remember. The scenes in the police station and in an empty parking lot are classics. Hysterical!
Not quite at the level of Wedding Crashers or Old School, but very humorous movie from Vince Vaughn and Reese Witherspoon. The nativity scene featuring Vaughn as Joseph is not to be missed.