I'll be honest - Shaun of the Dead is the only one I've seen. I've always felt weird about zombie movies, because like Westerns, without having seen any they all feel very samey. So I wouldn't know where to start watching.
I have been told by aficionados that shaun of the dead's zombies are pretty good, authentic even. In modern times there is a biozombie trend, when they aren't really "undead" so much as a sick human (eg I am Legend, 28 days later etc). I am not sure if it co-incides, but these biozombies seem to have enhanced reflexes, strength and hearing and speed etc... (whereas the old school ones were slow, sad things).
Personally, from a startup perspective, I'd be more inclined to go with a shambling type zombie, purely because keyframing the animation can be achieved fairly effectively with python scripts and then motions adjusted with bezier curves on an individual basis.
Doing more with less basically.
Also, stylistically I think the whole "tortoise and the hare" effect with fast protagonists and slow moving, shambling antagonists is quite amusing.