--any sequel after American Pie 2 (the first one was pretty much a classic, AP2 was pretty good, but American Wedding was awful and I have no plans to ever see any of the straight to DVD sequels).
--Batman Forever and Batman & Robin (IMO, Michael Keaton was light years better than either Val Kilmer or George Clooney)
--Ocean's Twelve (just way too many big stars, and absolutely had no senseable plot whatsoever)
--the Friday sequels (as much as I grown to like Mike Epps, those movies lost its spark without Chris Tucker being there)
--Revenge of the Nerds 3 and 4 (you can't make made-for-TV versions look as good as the original theaterical versions...Nerds 1 was a classic, and Nerds 2 was decent, but not as good as the first)
--Major League 2 and 3 (not only did it switch studios--the first one was made by Paramount, the last two by Warner Bros.--but you also replace Omar Epps for Wesley Snipes as Willie Mays Hayes, and it looked like the Warners didn't pour much money into the last two movies like Paramount did for the first one)
--House Party 4 (probably the worst movie I ever seen, and it was so bad, I don't even consider this movie as part of the House Party franchise. First off, no Kid or Play in this one, and was really LOW budget...and second, you had IMX/Immature in the lead roles and a bunch of no-name actors. HP4 pisses on the "legacy" of the first three movies. You, me, and a few of us on the board can put a hundred dollars together and make a better movie.)