Dragon's Lair, Space Ace, and Braindead 13. Fantastic animation, crap games. But frustrating as they are I just can't stop playing them once I get started.
In that same vein, all games by American Laser Games (Mad Dog McCree, among others). Nothing like bad guys falling down in an extremely over exaggerated manner when you shoot em.
Most FMV games just tend to have some quirky charm that makes them worthwhile for me.