3. Mark Hamill - Star Wars (Original Trilogy)
The culprit? George Lucas. The ultimate scifi epic trilogy put Hamill on the intergalactic Hollywood map, but also boxed him into a corner that no actor would ever want to be in: forever remembered as one character. For those of us who grew up with Batman: The Animated Series, however, we know him as the ultimate incarnation of the Joker outside of Heath Ledger, but in terms of his film career, Hamill was forever dogged by his role as Luke Skywalker, the ultimate zero-to-hero story. And while I don't think anybody else could have given Luke the gravitas and innocence that has become so central to the character and his journey, I do think Lucas inadvertently hindered the rest of Hamill's career by giving him such a profound and epic debut. It's on the same level as Elijah Wood and
Lord of the Rings, to use a more recent example. So while not necessarily "ruined" (I can't wait to see Hamill return as Luke in J. J. Abrams'
Episode VII), it severely limited his marketability as an actor from being "Mark Hamill" to simply "Luke Skywalker."