Zombieland was hilarious. I would also recommend seeing another movie where Jesse Eisenburg plays a similarly anxious character, Adventureland. Adventureland is one of my favorites. Lately it seems R rated comedies either stray towards unrealistic (though very funny) adventures such as Superbad, or aim for meaningful stories with believable characters such as Funny People, which end up being not as funny. Adventureland is a rare movie that manages to be very funny and also have a deep meaningful story and believable characters.