Two that come to mind for me are Ben Affleck and Cameron Diaz. I'm sure lots of people like them (they must do, to be successful) but they really irritate me and their presence can almost ruin a film.
I'm not too sure about Ben Affleck's popularity. If people like him, why are they not seeing his movies? And he's concerned about that too which is why he's gonna try directing instead.
My least favorite actor has to be Wil Smith. I used to like him, but now he's starting to annoy me. He finished filming the horror flick "I Am Legend" and if he cracks one more of his predictably bad funny one-liners, then I'm gonna jump out of a window!
Oh that's good news about Ben Affleck - I hope he never appears on screen again (including stupid Lynx adverts). I'll more than likely avoid any films he directs too.
I'm not too keen on Will Smith's films, they can be self-indulgent (he seemed to have caught Kevin Costner's 'I want to play heroes' bug), though he seems a nice guy in interviews.
Keira Knightley and Jen Aniston are two that instantly stand out for me on the actress side.
Oh and Vince Vaughn is an actor I can't stand along with Jim Carrey. I used to like Carrey but he just grates on me now.
Kirsten Dunst - not sure why, but I find her physically repulsive.
I also can't stand Jim Carrey - but he just iritates me, doesn't make me feel sick...
For me I can't stand Kristen Dunst, Scarlette Johansson, Steven Segal, Jean Claude Van Damme, Matt Damon, Angelina Jolie, Jennifer Aniston, Jude Law, ...I could go on and on and on
John Malcovich - horrible, creepy face
Edward Norton - he's a shockingly wooden actor
Nicolas Cage - horrible, mean face
Sigourney Weaver - contrived name, contrived actor
Holly Hunter - what an annoying voice
Ben Affleck - just don't think he's very good
Claire Danes. I get the feeling she thinks she is alot better than she actually is. Yes Claire, you were very good in "My So Called Life" but what exactly have you done of any relevance since? She is dull dull dull.
Plus she is a big old beeeyatch for having an affair with Billy Crudup that led to him leaving Mary Louise Parker when she was seven months pregnant.