In no particular order:
Santa and the Ice Cream Bunny
The Beast of Yucca Flats
Red Zone Cuba/Night Train to Mundo Fine
Birdemic
Manos: The Hands of Fate
Which segways nicely into my question: do episodes of mst3k count?
The problem with the movies shown on MST3K is that most of them are edited to fit the duration of the episode. The editing is usually a couple of minutes and in extreme cases (Like Marooned, or "Space Travelers" as the version the guys got was called) it's more than 15 minutes.
Anyway, I doubt the cuts really matter at all considering the terrible movies that they show there, so I guess they should count. No one says you have to watch 100% of the movie to rate it one of the worst ever, I mean, kind of the point of the worst movie ever is that it's so bad that you either lose your concentration and stop caring about it, or you fast forward the thing (or leave the theater or turn off the TV or whatever)
A lot of the movies shown in MST3K are on youtube in their original form, I've been watching some of them lately (Today it was Teenagers from Outer Space and yesterday it was The Giant Gila Monster for instance)
I recently saw their version of The Castle of Fu Manchu and it's reputation wasn't really exaggerated, it's truly a terrible movie.
It's hard for me to pick one non MST3K movie as the worst since I usually stop watching those things halfway trough. I also take precautions when going to the cinema, so I can see a movie that I'm positive will not be so bad that I would want it to burn in hell, So I never have to leave the cinema in disgust
Oh yeah, I only left once, like 10 years ago 15 minutes before "The Mexican" ended. That movie was a torturous experience, I felt like I was being waterboarded or something. I also fell asleep during "The Two Towers". Other than that, my record at the cinema is pretty good
