My least favorite controller is the Intellivision one.
Holy crap that thing is alsmot physically painful to use. I still have the intellivision that my dad has had forever, the controller totally kills it.
Yeah!
It's actually not bad for certain types of games, though. You get used to the layout. But then the buttons stick or are hard to press, but such is the technology of the day.
But there are some pretty friggin' awesome games for it. Mmm, Pinball, Bump&Jump, AD&D, D&D, etc.