My favourite zombie film is probably Peter Jackson's Braindead, also known as Dead Alive. The main character Lionel who is oppressed by his evil mother and eventually tries to do the responsible thing (like tying up zombies in his basement and feeding them custard) .. is just a brilliant character. The whole movie is utterly sick and twisted yet manages to tell a story of some kind of humanity. Plus, it's hilarious!
You can't call yourself a zombie movie connoiseur if you haven't seen this