Here's a list of people who provide the voices of various video game characters.
Charles Martinet: I'm pretty sure most of you know who this fellow is. He also does the voices of Luigi, Wario, Wauligi, and Toadsworth.
John DiMaggio: The voice of Marcus Fenix from Gears of War 1/2. His other roles include Wakka and Kimahri from FFX, Migelo from FFXII, and Bender from the TV show Futurama.
Ikue Ōtani: The voice of Pikachu from the Pokemon series and Super Smash Bros.
Ryan Drummond: Voice of Sonic from Sonic Advance 3, and Sonic Adventure 1/2.
Nolan North: He is the voice of Nathan Drake from Uncharted and soon Uncharted 2. He also the voiced the Prince from in the newest installment of Prince of Persia.
Haley Joel Osment: He plays Sora in the Kingdom Hearts series. He is also known for his role as Cole in the movie the Sixth Sense.
Hayden Panettiere: The voice of Kairi in Kingdom Hearts. She is also known for her role as Claire Bennet in the TV series Heroes.
Matt McKenzie: The voice of Auron from Final Fantasy X.
David Hayter: Last but certainly not least is the voice of Solid Snake from the Meat Gear Solid Series.