I'm going to be a maverick and suggest Cave Story on the 3DS. Laugh as much as you like; it only strengthens my resolve. I'll probably get Sonic Generations over a Boxing Day sale. Allow me to explain, if it helps:
Skyrim
I never really got into Fallout 3 or Knights of the Old Republic, both massive, sandboxy WRPGs, and I doubt I'd do any better with this massive, sandboxy WRPG.
Ultimate Marvel vs Capcom 3
Don't have a console that runs it and I'm not into fighting games, regardless of how much fanservice they provide. Not that much of a Capcom diehard, anyway.
Modern Warfare 3
I played the campaign of MW1 and sunk about 5 hours, total, maybe, into the multiplayer. I've also spent about 15 hours (of actual playtime) in Team Fortress 2, and that's all the multiplayer shooting I'll ever need.
Sonic Generations
I already said I'm interested in this one, but Cave Story comes first since that's already on pre-order.
Skyward Sword
Ditto for this, except that I haven't mentioned it yet.