I have to agree with so many on here: World of Warcraft is king, but I do enjoy some good Mario Kart and Starcraft games occasionally.
Play free online games with the Chevron Cars! You'll find dozens of free games, including Car Games, Arcade Games, Puzzle Games, Card Games and lots of other fun Kids' Games to choose from. Look for the games with a part of the score board star to track your scores on the new Game Scores Page.