Yeah, the 90s were a good time for movies that could not have been mainstream in any other decade. I'd place Judge Dredd, Demolition Man and Total Recall in the same "corny, but excellent" league as the 5th Element.
Then you had unofficial double features of sorts: Smoke/ Blue In The Face, Casino/ Goodfellas.
12 Monkeys needs to be mentioned as well, it's probably the most palatable movie on my list.
In the "disconcerting, but unforgettable" league, I'd place As Good As It Gets, The Crossing Guard and, of course, the grisly "8 mm."