I can't speak for the 360, but the ps3 has these notable games hitting the system this year:
MGS4
LittleBigPlanet
Resistance 2
Tekken 6
Socom: Confrontation
As well as some smaller titles like Valkyria Chronicles, Siren: Blood Curse, etc.
MGS4 and LBP are enough for me. Both are GotY contenders, imo, and LBP looks like it could be my favorite game since OoT.