Wii- Super Mario Galaxy
PS3 - Uncharted 2
360 - Halo 3
DS - Grand Theft Auto: Chinatown Wars
PSP- God of War: Chains of Olympus


No, I didn't play with any of these, but at least my list beats yours.

Wii - No More Heroes

Xbox 360 - Fallout 3

PS3 - MGS4

NDS - Castlevania:  Dawn of Sorrow

PSP - MGS:  Portable Ops

(Granted, MGS4 is the only PS3 game I've ever played ... and this could probably be amended in a few months; post NSMB and DSi purchase)

360: Mass Effect

PS3: Uncharted 2

Wii: Metroid Trilogy

PC: Civilization IV

Multiplat: Fallout 3 GOTY edition

Not into Handhelds...

PS3: MGS4
PSP: GTA: Vice City stories
Wii: Wii Sports
DS: GTA: Chinatown Wars

I have a three way tie for the ps3 Uncharted, Trine, and Demons Souls.
For the psp :Dissidia
Don't have a wii or a DS.

360: gears of war 2
ps3: metal gear solid 4
Psp: dissidia: final fantasy
ds: pokemon platnium
wii: fire emblem, radiant dawn

360- Forza 3

PS3 - MGS4

DS - Ouendan 2

Wii - Sin & Punishment 2 and Fatal Frame 4

Wii : Super Mario Galaxy
DS : LOZ - Phantom Hourglass -
PC : Prince of Persia NextGen.

My future fave games this gen.

Wii : ZELDA Wii
DS : LOZ - Spirit Tracks -
PC : Diablo III

Wii - Super Smash Bros Brawl
DS - Legend of Zelda: Phantom Hourglass (soon to be replaced by by Spirit Tracks methinks)
360 - GTAIV: Episodes From Liberty City

Wii:super mario galaxy
ps3:little big planet
nds:yu-gi-oh troubador... it was hard to pick for ds...