I loved it too! Everyone seems surprised that it is actually a genuinely good film.
Yes, it was frequently hilarious, but all the characters were pretty well played, and I sympathised with them a lot more than I did in Flightplan or Redeye.
There were a few subtleties too. As Newsnight pointed out, there is a snake featured whose venom has a very hard-to-find antidote. The snake is from the Middle East, of course...
Oh, there was even a snake in the episode of Tales of the Unexpected just now.