Grand Theft Auto IV!!!
The game was awarded by Spike TV's 2008 Video Game awards (can't remember the exact date) although the it is banned by some countries due to its social immorality influence on gamers especially to the under-aged.
I'm not a Grand Theft Auto (GTA) enthusiast but I played three of its installments, GTA 2, Vice City, and San Andres, and it was so fun killing people, flying over the city, destroying police vehicles, helicopters, and many more.
IMO, what made it won as the Video Game of 2008 is because of the great freedom it may give the player. What I mean is, you can make crimes and escape from the law. Also, activating its cheat codes makes it more fun. We do wanna break human laws because it's so boring to be so disciplined, aren't we? This game just unleashes the crime potential of players.
But players must not apply these acts to real life because life isn't a video game. Life is real; it isn't a game that you can go back to time by loading your saved game. So don't let this game devour your mind from the real world.