Here are, in no particular order, three of the worst movies I've ever seen:
Mr. Wrong: This movie is wrong. Poor Ellen. I have liked Bill Pullman in other movies, but this was just so un-funny. I spent the last half of the movie cringing.
Godzilla (1998): I like Matthew Broderick, so I tried hard to like this movie, but it's usually a bad sign when you want the monster to win. Seriously, if the monster had come up on land and chomped all the people, the movie would have been improved 100%. I have rarely been so tempted to leave the theatre in the middle of a film.
Down to Earth: This is one of those movies where all the funny parts were in the previews, except that even the funny parts weren't that funny. I didn't even crack a smile. It was just tedious. Once again, I seriously considered leaving halfway through the film. But I just kept saying to myself, "It's Chris Rock! Surely this gets funnier?". But, alas, it did not.
I'm pretty forgiving of movies. So if I hate something, it's usually really, really bad.