My favorite zombie film is 28 days later. The way its set in London is really cool, and I like the way they've made it more realistic by taking away the undead aspect to it, a nice twist.
Although, I'm a bit wary of recent zombie films. I watched Resident Evil: Extinction and was left thinking... "Oh dear god, what you done to the resident evil series?!".. The first film was pretty hopeful, the second was ok and the third made me want to face palm, especially so at the way it ends. Is it just me or has it gone over the top now? >.>