For the gamer with a dark side... Tom Clancy's Splinter Cell: Double Agent (read our review)
Gaming is escapist entertainment in which we do things we'd never try in real life. From harassing a chicken in Zelda to flattening a policeman with your car in GTA, we all enjoy indulging the devil on our shoulder now and then. For the budding psychopath in your life (c'mon, it's you, isn't it?), this year's guiltiest pleasure is Splinter Cell: Double Agent. As government-badass-gone-truly-bad Sam Fisher, you can do more than just kill, maim and steal. You can betray your own beloved country and join up with a sinister terrorist organization. Whoa.
Don't worry, when the pressures of immorality become too heavy, you can always switch a few in-game decisions and - bam! - you're a patriotic superman again. What other holiday game lets you play both the hero and the anti-hero?
Runner-up: Saint's Row