Gears of War's protagonist Marcus Fenix is voiced by John Di Maggio, the same actor who voiced Bender in the television series Futurama. Aside from the hilarity of the two characters sounding completely different, it's great when an actor can pull off the "I would have never guessed that unless I read the credits" situation. Some readers may be old enough to remember the shock when you found out that Mark Hamill (Luke Skywalker in Star Wars) was the voice of The Joker on Batman: The Animated Series. Some other random trivia is Courtenay Taylor, who played lesbian Jedi Juhani in Star Wars: Knights of the Old Republic, was also the voice of those naughty twins from the beginning of God of War, numerous female characters in Everquest II and the voice of Wonder Woman in Justice League Heroes.
Searching through IMDB.com for your favorite games will unleash a treasure trove of voice actors you recognize from many different games and shows. If you are an anime fan, put in your favorite show and most of those actors are recognizable for their voice talents in many video games as well.