For most actors, winning an Oscar usually marks the single greatest moment in their careers. Having an Oscar under your belt is, after all, confirmation of years of hard work and dedication, the highest honour that your peers can gift upon you to show their admiration and respect, and the best possible guarantee that, hey, you're pretty good at acting, after all. Put simply, it's the most esteemed acting award available and winning one should - in theory - open up all kinds of possibilities, ventures, and the promise of more great movie roles. And whereas all that does happen to the majority of actors who find Oscar glory, sometimes winning the most prestigious acting award around can be something of a curse. That's to say, lots of actors have found themselves to be the toast of the movie scene one minute, only to try to merge with the industry afterwards to find that Hollywood doesn't really know what to do with them. Sometimes, of course, a couple of naff post-Oscar movie roles will prove fatal: you won't believe how quickly Hollywood can kill your career if you screw up, Academy Award or not. So here's 10 actors whose careers took a sudden nosedive the moment they became Oscar-winners. Although winning seemed to point them towards brighter futures than ever, it actually had the opposite effect entirely...