Haven't seen many of the movies mentioned, thankfully. I wouldn't include many movies that blow, simply because I knew it was highly probable they would blow before seeing them, and this is about shockingly bad. Some I found to be shocklingly bad-
Crotching Tiger, Hidden Dragon- Perhaps all the hype is what led to my totally disappointing experience? I've had friends argue its supposedly, many virtues to me, I didn't appreciate them evidently.
Back to the Future 2&3, Raiders 2&3, and Matrix 2&3, Jaws 2- I hadn't heard much about any of the first ones before buying a ticket for them, they all floored me as surprisingly great movie going experiences. I left them stoked. When you follow them up the way these did, it makes my list of shockingly bad.
Conan the Destroyer- Probably read everything Howard wrote, that got published, by the time I was 12. Loved the first movie, despite the butchering of the chronology and history of the character. The 2nd wasn't even worthy of the Comic books.