MSG 2 and 3 - that would help the sales of MSG1 on PSN
Team ICO - would help The Last Guardian sales
GTA series could be from GTA1 to GTA SA - no need for reasons
and some other games to help younger people to get into the stories of older games...
Proudest Platinums - BF: Bad Company, Killzone 2 , Battlefield 3 and GTA4