Would a top five be ok? A list like this could go on forever for most of us!
Return of the Living Dead – running zombies, talking corpses, an awesome eighties soundtrack, gothic boobies and Tarman. What more could anyone want? See also: Return of the Living Dead II
Dawn of the Dead (original) – the ultimate siege movie. See also: Dawn of the Dead 2004
Night of the Living Dead – the great grandfather of them all, you haven’t seen a zombie film until you have seen this one. See also: Night of the Living Dead 90
Brain Dead/Dead Alive – one of the sickest, bloodiest and most hilarious zombie films ever made. Watch out for those intestines! See also: Shaun of the Dead (not from OZ but a nice mix of horror and comedy)
Zombie Self-Defence Force - no one does dismembered limbs and robotic schoolgirls better than Japan. Watch out for those zombified babies! See also: STACY: Attack of the Schoolgirl Zombie
Honourable mentions: Day of the Dead (original), Land of the Dead, Last of the Living, Dead Snow, Dead Set, Wild Zero, Junk, Versus, Fido, The Undead, Dance of the Dead, Zombie Flesh Eaters, Zombie Diaries, [REC], 28 Days Later, 28 Weeks Later.
Hope that helps a little…