Breaking into film is a lifelong dream for many a struggling actor, and it's one which is notoriously difficult to achieve. But what about the few who hit the big time and are tipped for greatness, then just as quickly slip back into obscurity? The actors on this list all seemed to have true movie stardom ahead of them, only for their careers to stall before they even got going. Some had substance abuse problems, others were difficult to work with, and a few just consistently chose awful movies. Many continue to act, but never reached the dizzying heights which their early success seemed to guarantee. Robert De Niro can make as many terrible comedy films as he wants and unfortunately for all of us it seems that he wants to make a lot of them because he's still Robert De Niro at the end of the day, and he's got some (diminishing) goodwill built up. For the many actors who aren't Robert De Niro, Hollywood is still a cruel and fickle place. So get ready for a list which proves that talent only gets you so far, and that your dreams can be snatched away even if they come true. It's like all your favourite childhood films were lying to you.