Versus.
Not a classic zombie film, but it's fucking rad.
The director's Hollywood debut was Midnight Meat Train, which is a decent little horror staring just-before-fame Bradley Cooper. Based on a Clive Barker novel, it has a kind of Lovcraftian horror to it in places.
You should check out both even if the latter isn't zombies.
I was in Dead Set as a zombie. In most of the long-shots of the facility with the zombies hording the gate, you can see me and my friends shuffling in the background.