I don’t slate you even though I love Sean Penn…! On my list the number one is Jim Carrey. 
Jason Schwartzman.
leo dicapr because he’s always paired/supported with exceptionally good actors
brad because girls in the movie house always laugh at the wrong parts of the script
wil smith because his movies are remakes of ones that stand clearly in my long memory
adam sandler - dunno, i just don’t like his movies
cuba gooding - always made to look like a superman (or a magician)
clooney - unrealistic acting
roger moore - like clooney
any and all allegedly-comic movie actors. ugh. i’m looking at you, ben stiller, adam sandler, jim carrey and owen wilson. among many, many others.
tom cruise, robert redford, alec baldwin, matt damon, george clooney, leo decaprio, richard gere, and brad pitt. just… blech.
Jason Biggs. At least Schwartzman can act.
Amazing he stars in a new show with two well-established actresses (Greer, Chalke) and he’s the lead. Unbelievable.
-Joe
Woody Allen.
I can’t stand Forest Whitaker. He’s a normal, good-looking guy when he smiles but in most films he’s a somber, ugly dude with approximately 3 different expressions and really annoying diction.
Gerard Depardieu - he’s fat, icky, and French. shudder
I agree, Paul Rudd is a total douchebag.
Her mouth, her voice. I can’t stand the sound of her voice and I hate to watch her talk, even with the sound off. Other than that, I’ve got no problem with her.
I agree with scubaqueen on the allegedly-comic movie actors - particularly Ben Stiller and Will Farrell. Hate them both. Annoying, unfunny, and they try too damn hard.
Kristen Stewart. She needs to go away. This feeling has nothing to do with Twilight (though I hated that too). She always looks stoned. Actually, every time she opens her mouth and words come out, she sounds stoned too.
Steve Carell. Ugh. Ugly. Can’t act. Annoying voice. Annoying mannerisms. REALLY STUPID MOVIES!!!
Dane Cook. To me he seems like a big jerk jock who likes to sodomize the smaller nerdy boys in the locker room. As far as I know, he could be the sweetest guy in the world but every time I’ve seen or heard him, I feel unclean and a little vomitous.
Hmm, I can’t think of any others at the moment who make me feel stabby. Oh, wait…I lied…
Michael Cera, Ellen Page, and Jesse Eisenberg - but particularly Cera.
I would be curious if there are any comic actors you do like?
I like comedic actors. Certain comedic actors. In general, I like comedies with regular actors. I have found that a lot of “comedic actors” really aren’t funny - to me.
Steve Carell has never once made me crack a smile. In fact, I was pissed at my sister for convincing me to watch The 40-year-old Virgin. Most of his other movies, I haven’t voluntarily watched. I was usually just in the room, where the computer was, while SHE watched them. (I did like Bruce Almighty and Over the Hedge though but I don’t even remember him, or his voice being in either one).
Will Farrel made me laugh in 1 movie. I love Blades of Glory and I loved his character. Other than that, I have never seen a movie of his that I liked.
Ben Still in particular surprised me. Dodgeball was an AWESOME movie. His character was completely perfect. Other than that - I’ve got nothing.
I love Monty Python, George Carlin, and Mel Brooks. I also like some juvenile gross-out humor. I loved both Harold and Kumar movies. I loved both Clerks movies but Dogma was better than both. I even loved The Hangover.
My sister and I once did a test. We were going on a 5 hour drive. I brought Occupation: Foole (Carlin). She brought some Dane Cook mess. She lasted about 15 minutes into Carlin. I lasted about 10 into Cook. We listened to the radio the rest of the way.
It’s all about taste. I like gory horror movies and movies with subtitles and I hate Steve Carell. Many people hate gory or subtitled movies and adore Steve Carell. I love Monty Python (“Oh Eton and Madgalene. The hoop has an hole in. Of course it’s got a hole in, it wouldn’t be a hoop otherwise, would it, mush!” :D) while other people (my sister in particular) think it’s insanely stupid.
We both agree though, Simon Pegg and Nick Frost are wicked funny.
His entire role in The Iron Giant involved mumbling like he had brain damage. It’s the role he was born to play! 
Robert Patterson (?) - The vampire guy - I couldn’t care less about vampires or Twilight so I don’t hate him for that but he has some pale clammy look that just makes me feel uncomfortable as though he’s going to infect me with cholera. My wife wants to see that Water for Elephants flick and he looks the same in the previews so I’m really not looking forward to watching him for two hours.
The heavy breather known as **Jack Palance **sounds like the sleaziest of pervs. Makes me want to dial 911 every time he opens his mouth.
I haven’t seen everything she’s done, but she tends to play very prickly characters who don’t smile a lot. That could bug someone who’s expecting the women on his screen to be warm and welcoming.
(I don’t know if I’m defending her or him. :p)
Jerry O’Connell. He must know where the bodies are buried, because he has sucked the life out of every production where he’s been in the same area code ever since Stand By Me.
ETA: For just about any other actor, I’m willing to judge the role versus the person playing the role. True, some actors and actresses have a slew of astonishingly bad roles, but I won’t right off something just because Cage or Ferrell or whomever is in it.
Ok here is the real list
Sandra Bullock
The dancing guy in Scream
Keanu Reeves
ms Zelwegger
I double dare you to challenge this list
The dancing guy in Scream? What dancing guy?
Until I get clarification on who the dancing guy is, I can’t confirm that your list is supreme. However, you’re spot on with the other 3.
I have to disagree. Sandra Bullock will always be remembered by me as the lead chick in Demolition Man. Of course, I’ve only watched that, Speed, and was forced by my daughter to watch Miss Congeniality.
For me the number one has to be Ed Norton. I’m sorry but to me his performances always seem to have been phoned in by a length of 2x4.
John Malkovich. His character is always the low point in any film I’ve seen him in - and that’s saying a lot, considering my opinion of Burn After Reading.
He’s just… weird. And not a good weird.
not unless they were making films in the 30s and 40s - and they could do more than just comedy: william powell, cary grant, spencer tracy, myrna loy, ginger rogers, and so on.