To the point that you just can't even see a movie they're in?
I hate Jessica Chastain, I have no idea why. I saw an interview with her when The Debt was coming out and she struck me as so vapid and "fake artsy/smart" and ever since I want to vomit when I see her. I hate her to the point that she could be in a movie about my favorite topic by my favorite director written by my favorite writer starring all my favorite actors... and I still wouldn't see it.
I also hate Tom Hanks! DH is baffled by this but he had "The Terminal" on last night and all I did was dog him. I don't think he's a bad actor or anything... my feelings about him are complicated. I basically think he's way overrated. But I don't hate him quite to the level I do Jessica Chastain.
How about yours?