A few off the top of my head, in no particular order, without reasons :) – sorry will edit later…
Limbo Game
Darwinia & Rez & Geometry Wars Evolved
Little Big Planet
Alien Hominid
LocoRoco
God of War 1 & II
Half Life 2
Wik & the Fable of Souls
Oddworld series
Ico & Shadow
Viewtiful Joe