Hm,let's see.

DS:
Another Code
Shiren the Wanderer

PS3:
Dead Space
Folklore (Fav PS3 game!)
Metal Gear Solid 4
Mirror's Edge

Wii:
Let's Tap
Monster Hunter Tri
No More Heroes
Overlord
Little King's Story
Pikmin
Sakura Wars (Fav Wii game!)
Fragile

My overall favourite so far is Sakura Wars. Splendid game with alot of role-playing and funny dialogue. I have a feeling Fragile will rule them all once I play that one though.

PS2:
Metal Gear Solid 2
Prince of Persia SoT and WW
GTA III

PS3:
GoW Collection
MNR
CoD 4
Fallout 3
Red Dead Redemption

Edit: MNR is my favourite

I only bought Flower for the PS3 this year, due to it being on sale. I haven't seen anything good so far this year come out.

god of war 3, mass effect 2, resconance of fate,metro 2033, SOCOM confrontation, heavy rain, final fantasy 13, new super mario bros (DS), The legend of zelda spirit tracks, lost planet 2, battlefield bad company 2, just cause 2, darksiders, MAG, tom clancy splinter cell conviction, fable 2, pokemon heart gold, pokemon silver thingy :P but to tell u the truth the best was god of war 3!! but i bet red dead redemption will take that place soon! ;)

Tekken 6

Eternal  Sonata

Final Fantasy XIII

Dynasty Warriors 6

FolklorE

little BIG planet

Golden Axe: Beast Rider

inFamous

Eternal Sonata is by far my favourite. Incredble music, beautiful graphics, engaging story, innovative battle system and interesting characters make this one of the best games i've ever played.

PS3:
GOW3
Dante's Inferno
Red Dead Redemption

Red Dead Redemption is my favorite so far.

Wii:
Guitar Hero 5
Dead Space Extraction
Cursed Mountain
Silent Hill Shattered Memories
No More Heroes 2: Desperate Struggle
Shiren the Wanderer
Fragile Dreams: Farewell ruins of the moon
--------------------------------
Boom Blox Bash Party
A Boy and his blob

Those below the line I have not played yet, and I still have 2 more games in the mail.
My favorite by far is NO MORE HEROES 2, its just super crazy, the 8bit games are great and the combat is superb.

That's a lotta games, one a week.

PS1:

FF7
FF8
FF9
Crash Bandicoot
Crash Bandicoot: Warped

PS2:

FFX
FFX-2
Persona 3
Kingdom Hearts Re: Chain of Memories
Jak 2
Jak 3 

DS:

Trauma Center Under the Knife 2
Mario and Luigi: Bowser's Inside Story
Final Fantasy 4
Pokemon HeartGold

GC:

Baten Kaitos Origins
Tales of Symphonia

Wii:

New Super Mario Bros. Wii
Metroid Prime Trilogy

Virtual Console:

Ocarina of Time
Super Mario Kart
Paper Mario
Super Mario Bros.

360:

Final Fantasy 13

Final Fantasy 9 is my favorite. 

PS3 -

M.A.G.
Final Fantasy XIII
3D Dot Game Heroes
Red Dead Redemption
Resonance of Fate


Favorite -

3D Dot Game Heroes

Infamous
Bioshock
GT5 Prologue
Red Dead Redemption


So far Red Dead is the best and maybe Bioshock 2nd. They are all good though.