This nice little misogynistic movie, The Hangover, actually is rather entertaining, if you're willing to overlook it's anti-female attitude and buy into its improbable premise.
That is, four friends (each of a certain type, which we'll delineate momentarily) decide to head to Vegas for a wild night for one of the friends - Doug's- bachelor party (the wedding in this film is entirely ancillary). The wild night becomes a bit more wild than they anticipated when someone slips the group of "Micky." Three of the friends wake up the next morning with a tiger, a chicken, a baby, and a naked lady in their hotel room, entirely unable to remember the night before. Oh, and Doug is missing.
The log line makes a nice joke, but the real test in a movie like this is where they go from there. The movie is essentially a treasure hunt, as the free friends must use the clues they discover to re-trace their steps from the night before.
What makes the comedy here work, mostly, is that the friends are four distinct personality types: Doug is the cuddly, good-natured groom, who ends up getting the worst of it. Phil is the pretty-boy womanizer, who also happens to be the only married member of the bunch. Stu (played nicely by Ed Helms) is the neurotic dentist, who in his micky-induced stupor somehow pulls out one of his own teeth and marries a hot stripper; and Alan is the not-all-there, tag-along, brother-of-the-bride, in the nominal "John Belushi" role.
Naturally, the movie lavishes oodles of time nicely characterizing our four fellows, while reducing all the women in the film to caricatures (the bride, the whore, the police dyke).
Despite that, it has some good moments, and the comedy is more self deprecatory than mean (the film is a spiritual inheritor of the Meatballs and Caddyshack school). Some jokes work better than others (I found the gangster bits a bit lame, and the tiger more growl than bite, but I loved the naked Asian in the trunk of the car and some amusing bits involving a grade-school taser demonstration).
In other words, it's a light-hearted romp with a number of the standard "Daily Show"/"Saturday Night Live" graduates making appearances; on the whole probably more entertaining than egregious. It won't end up in any comedy hall of fame: However, the final sixty seconds of the movie - when the four friends find a camera and are finally able to see the shots of what happened that night in sequence - are laugh-out-loud hilarious, and worth sitting through the film to see.