I voted "multitask", but really that isn't very accurate.
Generally, I play around 3 games at a time, and my gaming goes something like this:
Casual Game. This is a quick, easy to get into game that never gets olds. A fighting a game, an old platform hopper, or multiplayer game.
Sports Game. My three big sports are Baseball, Basketball, and Football. And I'm usually playing a game (sometimes two) during the season.
Current obsession. This is the game that I spend MOST of my time with, and that I come back to again and again, until its finished.
So right now, it looks something like this:
Casual Game= Left 4 Dead
Sports Game= NBA 2K11
Current Obsession= Shogun 2 Total War (before Shogun it was Fallout 3)
Oh sure, I'll play around with a game here, or try out something there, but as far as consistency goes, I never really have more than one "Current obsession" at a time.