I've been a PS3 Gamer his whole generation, so i do not know all of the 360 titles, though the ones i recognize are here because of their impact on gaming.
GTA IV
Skyrim/Oblivion
Fallout 3
GoW
Halo 3
Batman Arkham Asylum
Mass Effect series
Uncharted
Bioshock
Saints Row 2
CoD 4
Deus Ex: Human Revolution
Assassin's Creed
Journey
Limbo
Red Dead Redemption
Battlefield 3
The Last of Us (Premature, but still looks like it's going to be an instant classic)
GTA V (again, not out, but GTA is always a classic)
L.A. Noire
Flower
Portal
TF2
Infamous
Legend of Zelda: Twilight Princess
Super Mario Galaxy
Wii Fit
Bastion
I tried to get in a good mix of cross platform games as well as exclusives from both consoles and indie games that have been much lauded and loved, this generation has seen much improvement in gaming quality (Despite what it looks like) and indie games have benefited much from PSN, Steam and the XBLA, introducing millions to some truly great titles.
there are probably more games out there that my list misses, but otheres have what i don't
GTA IV
Skyrim/Oblivion
Fallout 3
GoW
Halo 3
Batman Arkham Asylum
Mass Effect series
Uncharted
Bioshock
Saints Row 2
CoD 4
Deus Ex: Human Revolution
Assassin's Creed
Journey
Limbo
Red Dead Redemption
Battlefield 3
The Last of Us (Premature, but still looks like it's going to be an instant classic)
GTA V (again, not out, but GTA is always a classic)
L.A. Noire
Flower
Portal
TF2
Infamous
Legend of Zelda: Twilight Princess
Super Mario Galaxy
Wii Fit
Bastion
I tried to get in a good mix of cross platform games as well as exclusives from both consoles and indie games that have been much lauded and loved, this generation has seen much improvement in gaming quality (Despite what it looks like) and indie games have benefited much from PSN, Steam and the XBLA, introducing millions to some truly great titles.
there are probably more games out there that my list misses, but otheres have what i don't