I agree with Jack. I haven't played it yet, but God of War 2 is supposed to be great. And Super Paper Mario JUST came out for the wii.
Coming out over the next few months will be several very promising games. In a couple weeks, Pokemon Diamonod and Pearl will be coming out (not my thing, but a lot of people like it), halo 2's coming to the P.C, C&C 3 is coming to the 360, Mass Effect is coming in May or June, Half Life 2 Episiode 2 (worst title EVER) is in June, Ninja Gaiden is coming to the PS3 in June. Over the summer, Bioshock, Blue Dragon, Lair, Heavenly Sword, a Civ 4 expansion, and a Medieval 2 Total War expansion. Then, there are tons of huge games towards the holiday season.