I'd like to see Fallout 3 & New Vegas rereleased for console platforms, considering the original versions were buggy and would suffer from poor performance once your save file went over a certain size.
The first two Call Of Duty Black Ops games which I feel were more popular than it's Modern Warfare counterparts that had their own remasters.
Blur
On the PlayStation side I'd like to see both Killzone and the Resistance series of games remastered, you could tell there was a lot of detail in those games that were hampered by the 720p resolution, along with Motorstorm and Infamous.
For Xbox, The early Rare 360 games and PGR 3&4 would be good, but music and licensing issues make that unfeasible.