My vote would also go to Sony. I love my Xbox and it is my primary gaming device but that is because of the controller, not because of their games. Sony has had themselves some stumbles but for the most part, their games are always A+
I really liked Nintendo's 2D stuff but for whatever reason, their 3D stuff just never clicks with me, which cuts out a huge chunk of their library from my wheelhouse.
Microsoft....really doesn't have a whole lot. I got bored of Gears of War at 3, Halo is falling apart and....uh....other stuff they make probably exists.