CLARIFICATION: The Game Critics Awards ballot I filled out was to create the list of nominees. I submitted 3-5 picks for each of the categories below, but in the interest of brevity I've just included my top pick for each category. It may end up that some or all of my top picks won't be final nominees in the awards, since it's based on a consensus of the judges.
With that out of the way, here are my top picks for each category:
Best in Show: "Splinter Cell: Conviction"
Best Original Game: "Scribblenauts"
Best Game, Console: "Splinter Cell: Conviction"
Best Game, Handheld: "Scribblenauts"
Best Game, PC: "Alpha Protocol"
Best Hardware/Peripheral: "Project Natal"
Best Action Game: "Modern Warfare 2"
Best Action/Adventure Game: "Splinter Cell: Conviction"
Best RPG: "Alpha Protocol"
Best Racing Game: "Split/Second"
Best Social/Casual Game: "Ricochet" (Project Natal's ball-bouncing game)
Best Online Multiplayer: "MAG"
Best Graphics: "Uncharted 2"
Best Sound: "Uncharted 2"
Notable runners-up include: "Brutal Legend," "Heavy Rain," "DJ Hero," "Lost Planet 2," "Homefront" and "ModNation Racers." I was a little bummed not to see a downloadable games category this year, as "Shadow Complex" and "PixelJunk Shooter" definitely deserve nods, but there's always next year!