Even though I'm a Nintendo fanboy I'd have to go with Microsoft. I'm hoping they do a lot with their motion/voice sensor. That was a big plus for me.
I'd never choose Sony due to the fact I'm not a fan of many of their games.
Nintendo doesn't have much coming out: Super Mario Galaxy, IMO, was a flop, I prefer the classic mario games. And they're just milking Metroid now, I mean, Corruption was supposed to be the final game but nooo, they had to make another