2. Leonardo DiCaprio (Col. Hans Landa, Inglourious Basterds)
I was, like so many others, extremely disappointed when the news broke that Leonardo DiCaprio was no longer going to play Colonel Hans Landa in Inglourious Basterds, given the edginess of the role and the potential it afforded DiCaprio to further dispense with his dreamboat image that plagued him for so much of his early career. Details about Leo's departure remain sketchy - some say Tarantino decided he wanted a German actor instead, others specify the non-committal "creative differences" - yet few of us could have anticipated that it would lead to such a fantastic, happy accident. Christoph Waltz of course completely made the role his own, winning the Academy Award for Best Supporting Actor for his deliciously demented rendition of the sadistic Colonel, and it all worked out swimmingly because DiCaprio gave us a performance he was far better suited for, as deranged plantation owner Calvin Candie in Django Unchained.