We know. Trust us, we know. Sequels are widely regarded as instinctive, uninspired cash-ins nowadays, clogging up the studio release slates like particularly stubborn bowel movements. Sure, they have to come out, but nobody really enjoys them. They're just habit. Still, not all sequels are bad. In fact, on rare occasion, they even surpass the originals. That's why it's still so easy to get excited about the announcement of a follow-up to a beloved film. The possibilities still seem endless, even if there's a much grimmer (or worse, blander) reality lurking just around the category. Some proposed sequels never actually come to light, though, even after they've been all but guaranteed by the trade magazines. Financial woes, sudden disinterest from a key cast member, and various unforeseen misadventures can cause an encouraging sequel to come grinding to a halt. Here are ten movies that have all been shelved for one reason or another, in spite of their promise and guaranteed ass-kickery. And that's just...very sad. But that doesn't mean we should give up on them entirely. After all, it took 20 years before we finally got a sequel to Dumb & Dumber! (Okay, maybe that was a bad example.)