We’ve all done it: turned down an offer for something that seemed like a good opportunity but didn’t quite feel like the right fit. Now imagine doing the same, but as a Hollywood actor. And then you tune into the flick you’ve turned down, and it’s Titanic or The Princess Bride or Pretty Woman. Of course, the 40 actors on this list ended up doing just fine in their careers. But it’s crazy to think they could have starred in these iconic roles – if only they would have said yes.