The Hangover is, quite predictably, a great hangover movie. It follows a bunch of guys waking up in Vegas after the bachelor party to end all bachelor parties. Extreme and wacky remnants then convince us just how extreme and wacky the previous night was. The most immediate problem confronting them - they've lost the groom.
This is Dude, Where's My Car? for basically the same audience, although we're slightly older and slightly more sophisticated now. It's not to be taken too seriously. The opening half an hour is a succession of montages set to R&B songs. Slow motion driving to Vegas. Slow motion casino walking. And of course, slow motion bikini babes. All this is set to exactly the kind of music you love when you're drunk.
The main problem with The Hangover is its marketing. If you go to a cinema on even a semi-regular basis, you've seen the preview of this film at least a few times. As such, you've seen most of the major set-pieces and a fair chunk of the hilarity. These aren't the only jokes, but the others are mainly designed to set up the ones you've seen. As such, it's like being surrounded by a bunch of stoners - you can appreciate why they're laughing, but you just can't raise a guffaw.
The ensemble works well. Everyone has their role and fulfils it admirably. Bradley Cooper is the standout in his first foray out of a sleazy bad guy role...into a sleazy good guy role. A solid comedy, but detract half a star if you've seen the trailer.