What characters would they add?
Here's a complete list of what people have said
My favourite characters are underlined.
Ratchet and Clank
Brave (played on a demo)
Soul Calibur 3 Character (SC3 was exclusive to PS2)
Megaman if you like that
Street Fighter Character for the old school
Heavenly Sword Character.
The Lair Dragon could be included in some sort of way
The Shadow of the Coloussus Character would be one (Colossi would be a stage)
Hero from Dragon Quest 8
arc the lad
Jessica (Dragon Quest 8)
Riku (Kingdom Hearts)
Rayman (Exclusive on PS1 i think)
Your Home Character
Uncharted Drake's Fortune Character
Rogue Galaxy Character
Pacman (Pacman World 3)
Prince of Persia
Kay (Legend of Kay)
Kya (Kya Dark Lineage)
Maximo (Maximo vs the army of Zin)
Parappa The Rapper
Dead Or Alive Character
Banjo Kazooie (Rare)
Blue Dragon Character
Naruto (had an exclusive game on 360 from Ubisoft)
Any more XBOX exclusives?