Just saw
Zombieland, and true to the buzz, it was immensely entertaining. So, why did I find the last third of it lacking?
Spoiler:
The blend of comedy and horror was pretty much perfect for the first two thirds of the film, but once MAJOR SPOILER
The tone of the movie shifted to something much tamer - essentially it became skit comedy, with no emotional stakes whatsoever.
I still had a really good time, but came away thinking of it as kind of a wasted opportunity. Still worth a look, and if you aren't bothered by the thing I talked about in the spoiler above, hang out until the credits are over.