The other day my sibling and I were discussing Olivia Wilde, the actress who plays "13" on House. I don't remember how the conversation was started or what it was about, really, but I referred to her as "13" and James referred to her as "Jenny Riley," which was the character she played on NBC's short-lived crime drama The Black Donnellys. (For the record, I always think of her as Alex, Marissa's experimental lesbian love interest on The O.C.) From that point we started talking about how some actors are so identified with roles that they've played, that you have trouble separating the two.
I think it's a little different between t.v. stars and movies stars, maybe because you have so much more time invested with t.v. stars. T.V. stars tend to become the character they portray, whereas movie stars just remain themselves in every movie there in.
Actually the best example of this (in terms of movies, anyway) is probably John Wayne. I don't think anyone could argue against the point that he was basically John Wayne in every movie he ever made. I guess with movies, that's what makes the star.
There's something about their personality or appearance that appeals to moviegoers and that's why people pay to see them over and over again - but only as long as they have that bit of mojo. Poor Meg Ryan is an excellent example of this. In the late 90s and early 00s, she was one of the reigning ladies of romantic comedies. But when was the last time she was a lead in a truly successful movie?
Likewise, Sarah Michelle Gellar was so fantastic as Buffy that people have a hard time separating her from that role. Think about it - even if you weren't a fan of the show, when you see her or hear about her, you instantly associate her with Buffy. Hey! It's Buffy in a movie! or Buffy guesting on a t.v. show!
Same with Kristen Bell. Every time I see her, I think Veronica Mars. Hey! Veronica Mars is on Heroes or why is Veronica telling us about the lives of Upper East siders on Gossip Girl? You know she hates oh-niners.
Think about the cast of Cheers. When you see George Wendt come on screen, you think, "Norm!" and maybe even find yourself calling it out. Ted Danson, even though he's had successful runs on other shows, will always be Sam "Mayday" Malone. You get the point.
I'm not sure anymore where I was going with this post, so I'll stop now, lol.
What actor do you associate so strongly with a character that they've played that you have trouble separating them?