We need to come up with a new genre of movies to categorize those that are so spectacularly awful that you just can't look away. A good name for the genre would be "Train Wrecks." Mansquito is a perfect example of this type of movie. It was so bad that you had to watch it just to see what came up next. I stayed with the movie just to see what kind of situation the writers would put the seven-foot tall Mansquito in after the commercials. Mansquito v. SWAT team? Done. Mansquito v. exloding building? Done. Mansquito v. scientists? Done. Cheesy lines? How about "He's more mosquito than man!" The movie was great, but probably not in the way that the writers intended.
I think Space Truckers also belongs here, though I know several of my friends will tell me I am wrong.
Any more suggestions? Put them in the comments, and I will update the post with them.