Like others have said, Napoleon Dynamite fits the category well. I think another film would be The Other Guys. I hated that film at first because I thought it was horrible in general, but since my first time I have seen it I like it a bit more.
Anyone remember Samurai Cop? The movie about a dude who walks around his city and sometimes gets shot at, and chills at home in a speedo? Me neither. I think what makes the movie so bad it's good is just about everything, from poorly edited chase scenes, to terrible acting, to speeches even George Bush would be ashamed of.
Click (Adam Sandler) was a good movie, in essence, but that's because it was one of those slapstick comedies that doesn't make a whole lot of sense, is probably really, really terrible when you think about it, but jesus christ you're watching it for the twelfth time tonight. Then again, that's how I feel about most movies nowadays.