Stag do, Vegas, booze, drugs, strippers, vomiting and the casting of Heather Graham - The Hangover boats a mighty number of signifiers that suggest that it was going for nothing nobler than the lowest common denominator. Which makes it all the more prop-worthy that it went on to become arguably the cult comedy hit of the year.

The Hangover gets off to a flier: we quickly discover that the wedding-day plans of Doug (Justin Bartha) and Tracey are looking royally screwed. Doug's friend Phil (Bradley Cooper) calls to tell her that he isn't going to make it to the ceremony - the stag do got out of hand and now the groom is missing somewhere in Vegas.

Picking up amidst the debris of the morning after, Phil, Stu (Ed Helms) and Doug's future brother-in-law, the stupendously maladjusted idiot Alan (Zach Galifianakis) need to find their buddy, and work out what the hell happened the night before.

With heads filled with the kind of fuzziness that comes from a serious night's caning and a collective black-out that means they have no memory of the night's shenanigans, the guys attempt to piece it all together from clues left in the wake of their carnage, including a lost baby, Mike Tyson's tiger, a stripper, a stolen police car and the campest, most bad-assest Chinese character ever committed to film. 

Despite setting up for the broadest, crassest, laddiest end of the market, The Hangover is a pretty smart, well-judged affair - by steering away from the raucous events of the night before and focusing instead on the painful void the lads deal with the next day and the hunt for Doug, it's less predictable - with it's switching timeframe it's kinda like Memento with a massive bar bill.

Without Galafiankis the film would have been a lot less fun, so give thanks that he is in. While the rest of the main characters have a bland everyman quality that lends a believable quality to the ridiculous scenario, his lowdown oddness and daisychain of bizarre one-liners dominate the laughs. He's not the sole source of mentalism, though - Ken Jeong's over-the-top fey mobster gloriously stomps all over proceedings in the final third, as Doug's whereabouts becomes clearer.