How about a few from the 80's (I didn't read all 25 or whatever pages in this thread, so bear with me). The 80's and early 90's had some exceptionally bad movies including(but certainly not limted to):
1) Howard the Duck (with "what's her name"?)
2) Johnny Dangerously (with Joe Piscopo)
3) Anything with "The Coreys" (Feldman & Haim)
4) Ed Wood (Johnny Depp... why did they make this film? Why not just give us the $?)
5) Cry Baby (another Johnny Depp classic from the 90's with a woman so ugly they named the character "Hatchet Face"