Super Mario Bros. The Movie (I have it on DVD)
You can tell the scheme was constantly changing in the script itself and was so bad that it only got half the money back that was put into it.
Anything after Scary Movie 3 in the parody series (except maybe Vampires Suck which is hilariously better written than the whole Twilight series).
Fred: The Movie and Fred 2
No idea why it got a sequel, the first one was terribly shitty and hearing that guy is finally getting his own tv show soon is even worse, he wasn't funny when he began, wasn't funny in either movie, and won't be funny when he gets his own tv show.