Rogue Trooper
Meltdown Man.
Dredd.
The Megacity vibe as a whole. It disturbed me as a kid, which goes to show just how good it was. Lasting impact. Loved it. Oh, and seamonkeys...:D Remember those ads?
PS - as an aside, the laster Dredd film with Urban, if you haven't watched it, it is actually a pretty good rendition of Dredd.