Zombieland was fun. A lot of fun. I don't have much experience with the horror comedy genre, but I do tend to enjoy the hijinks of regular horror movies more than the depressing, people are actually dying aspect. And since I recently learned that Jesse Eisenberg doesn't suck, I found this movie charming, silly, and, like I said, fun.
Zombieland is a road movie of sorts as the characters try to make their way to Pacific Playland - a fictitious amusement park outside of Los Angeles. The two most important things about road movies 1) avoid making them feel episodic and 2) make the characters who are on the road together fun as an ensemble. Zombieland achieved both of those and managed to give each of the characters a fairly focused and coherent arc in the process. Plus, it was funny.