Any and all made-for-video sequels of Disney animated movies. That should give you a lot to work with. Let's see... off the top of my head... Return of Jafar, Lion King II, Cinderella II, Pocahantas II, Hunchback of Notre Dame II (but then again, the original Pocahantas and Hunchback movies sucked, so...) and Return to Neverland, and I know there's more out there. Probably enough for a whole festival of pain in and of themselves.
Beyond that, Halloween 2, Men in Black II and Godzilla Raids Again (the first Godzilla sequel. No, it's not good. Even by Godzilla movie standards) all qualify.
Edit: I can't believe I forgot to mention Exorcist II: The Heretic.
Worst. Movie Sequel. Ever.
Demiurge out.