Way too many to remember them all, so I just list the ones that left the biggest impression:
Devil Summoner 1 - what an awesome game, don't understand the mediocre reviews my GOTY
Hot Shots Tennis PSP - If only every tennis game had this mechanics, I'd kill for a Topspin with this gameplay
Persona 4 - Well, everyone who played it know how good it is..
Fallout 2 - They actually improved everything that I hated about the first
Prey -Brilliant Sci-Fi shooter, hope we'll see a sequel some day
Limbo - Stunning artstyle, I want a jump and run with this engine!
Crackdown - Great concept but way too many enemies
GTA 4 TLAD - Better than the main game still not anywhere near as good as the PS2 ones
Bourne Identity - Boss fights with time limit and QTE? Fuck you whoever thought of this.
Splosion Man - Trial and Error with time limits and jumps that don't allow any mistake, still a good game, just not great
Tomb Raider Anniversary - If only every TR game was like this.
Halo 3 - Sooo great till the flood came..
Odins Sphere Having to play through the same game 7 times sure is fun! Well actually it's not.
Suikoden 3 You can play with a duck in your party, if that isn't great I don't know what is.
I think I'll write down what I play this year..