Damn, just reading the first half page makes me realize how cynical you all are. The Watchmen bad? How could it have been better? If you say follow the comic book closer, then I'm going to slap you. General moviegoers would not have liked the original ending. It worked great in a comic book, but not movies.
I was going to re-add Indiana Jones 4 to the list. I think it was more awful than Manos and Plan 9 put together. Both of those movies had a good idea that just was done wrong (wrong WRONG WRRROOOOONG!), but IJ4 had no idea where it was going the whole time, except for fulfilling Speilberg's desire to shoehorn aliens into everything (A.I. anyone?).