I made a list - 268 items on it.
It depends on what you are after:
Fast zombies - 28 Days/Weeks Later, prepare for the sequels
Slow: The Dead; Salvage
Zombie Nazis: The Outpost films
Comedy: Pride, Prejudice and Zombies; Harold's Gone Stiff; Cockneys vs Zombies
Kung-fu: Legend of the 7 Golden Vampires
TV: Dead Set (if you are familiar with Big Brother); In The Flesh; Zomboat; Derren Brown's Apocalypse
Early: Womaneater; Dr Blood's Coffin; The Plague of the Zombies; The Frozen Dead; The Oblong Box; Horror Express; Let Sleeping Corpses Lie
Worst: Doghouse - pisses me off thinking about that claptrap
Shorts: Danger 50,000 Zombies (you may recognise the stars), I also provide links to various other shorts in the list