I watched Return of the Living Dead (again). Most horror nerds will laugh, but I love this movie because it's the only well-regarded zombie flick that actually makes the zombies the primary threat. Unlike Romero's movies and those who've used Romero as a template, the living actually come together and strengthen each other. It's not civil strife and conflict that dooms them, but the sheer volume of the living dead.
I can't think of any other zombie movie that has went there.
Oh yeah, there's also Linnea Quigley and her nude graveyard dance. RIP Dan O'Bannon; you sure knew how to make a fun movie!