what is your favorite exclusive game for each system this gen ?

[r505Matt]

Xbox 360: Mass Effect 1+2 (the PC versions totally don't count)
PS3: Demon's Souls
Wii: NSMBWii
DS: ROCKET SLIME!
PSP: Dissidia
PC: L4D2 (the Xbox version totally doesn't count)
iPhone: Plants vs. Zombies (again...)