Who is your favorite voice actor and why

Nolan North he is  the Johnny Deep of video games due to his wide variety of roles

I only know Nolan north so I can't comment

Dave Wittenberg for his role as Welkin and Hans the pig in Valkyria Chronicles. Moioink indeed.
 
It seems he was in a bunch of games, including ODST, P4 and ME.

" I only know Nolan north so I can't comment "

...Who's Johnny Deep? 

Jennifer Hale. 
I can't say why but she just sounds right.

" ...Who's Johnny Deep?  "

I really like Seth Green as Joker in ME. I do like Nolan North as he's always good and is in a large quantity of games.

" Jennifer Hale. I can't say why but she just sounds right. "

Not going for strictly games, I'm a big fan of Tress Macneille. She's a pretty prolific voice actress and she's been around for a while, so it feels like she's always been there for me...

" @Tairoku said:

" ...Who's Johnny Deep?  "

I think he's a porn star.  I believe he was in "Who's Eating Gilbert's Grapes?"  My answer is John Dimaggio.  He's Bender on Futurama and Jake the Dog on Adventure Time.  Oh, and his in some shooting game with chainsaws. "

I ASK YOU.

" Dave Wittenberg for his role as Welkin and Hans the pig in Valkyria Chronicles. Moioink indeed.  It seems he was in a bunch of games, including ODST, P4 and ME. "

"

How can you deny the David Hayter sexy face? 
 

I ASK YOU.

"

I have to give Steve Downes some love for Master Chief. It may not be the most demanding role, but goddamn is that a cool, iconic voice.
 
Other than that, Rob Wiethoff as John Marston comes to mind. Probably my favorite performance of the year.

Fred Tatasciore for the win! He totally killed it as Saren in the first Mass Effect. He's also Mario in Assassin's Creed 2.
 
But he totally didn't quite kill it as those stupid "monsters" in the two Uncharted games.

Samuel L. Jackson

 Steve blum from Dawn of War 2 and other games.

Kevin Conroy FTW!!!!!! i dont care if he only does one role

Keith David
 
A great voice, with a lot of history with voice acting.

" Kevin Conroy FTW!!!!!! i dont care if he only does one role "

My favorite is Sarah Hamilton, the voice of April Ryan from The Longest Journey franchise. There's a couple of japanese ones I like: Norio Wakamoto and Mamiko Noto. I also like Tricia Helfer, Jennifer Hale, Mark Hamill, John DiMaggio and Dan Castellaneta. 

Jennifer Hale is a national treasure.  She played Jaden Korr in Star Wars Jedi Knight: Jedi Academy, Dynaheir in Baldur's Gate, Mazzy Fentan in Baldur's Gate II: Shadows of Amn and Throne of Bhaal, Bastila Shan in Star Wars: Knights of the Old Republic 1 and 2, female Commander Shepard in Mass Effect 1 and 2 among many others in film, television, and video games.

I agree with  Stete's comment from above, that her absolute best performances were in Mass Effect 1 and 2 and I don't remember any performance from any other voice actor that turned out so perfect.

Jennifer Hales performance in Mass Effect 1 and 2 was truly amazing.  Her voice was music to your ears, such that she could tell Commander Shepard's story so vividly that no visual aide was necessary.  Her voice compelled you to listen, -- a siren's song.  The intonation, inflection, emotion, presentation, and timing was right on the money for every word of dialogue.  As a female commander it was amazing that she could show compassion for victims but never lose her voice of authority.  She was kind, but not all mushy, at the same time you knew she was the commander in charge.  Her voice was that of a legendary great leader that masses of people flock to follow because they know that are part of something special.  Her renegade performance was shockingly good, as well. She made it feel so good to be bad.

P.S.

She will lend her voice to the Female Trooper in Star Wars: The Old Republic and reprise her role as female Commander Shepard in Mass Effect 3.

Man, I always forget how weird-looking David Hayter is, like David Spade's oafish older brother.
 
I think Nolan North will run away with this. After all, he is the only Voice Actor with an award solely dedicated to deciding which of his performances is best in any given year.

Steve Blum, because he's played so many characters its crazy and they're almost always deep voiced and awesome.