Worst zombie movie:
Land of the Dead, hands down. Not because of cheesy acting or low production values, but the entire premise was ridiculous. Intelligent zombies or zombies on a mission contradicts the entire idea of mindless flesh-eating zombies. Sorry, Romero, but you pooped on your own creation with that one.
Of course the remake of Dawn of the Dead stank on ice not just for being an obvious ripoff of 28 Days Later but also with its fast/slow zombies that ignored animal life, unlike the great classic Night of the Living Dead where the flesh-eating zombies ate every living thing they could find.
Off-topic: zombies aren't the only undead creatures. There are vampires, of course, but there are also mummies, revenants, frankensteins and others. So just because a movie like Army of Darkness has undead creatures, that doesn't make it a zombie movie.
I'm not sure how to classify the undead pirates in Pirates of the Caribbean but they certainly weren't zombies. They called themselves ghosts but ghosts are not corporeal.
