So we have to choose what retro games on XBLA or PSN we'd want remade into a full game? Or do you mean any retro game you want remade for XBLA/PSN or do you mean any retro game remade as a full game (Graphics etc)? Anyway I think I know what you meant so for my list of games I'd like to see Flashback, Road Rash and possibly Zool remade.
Well either remade a bit like Duke Nukem was or just added like Golden Axe with online play, leader boards and achievements. James Pond: Robocod and Zool 2 would be awesome on Live, I remember Flashback somewhat, I had it on my Amiga... it either didn’t work right or I got stuck on it as I remember never been able to get that far on it. Didn’t it have some amazing animated intro that was really advanced for the time?
Ah yes that’s it, it does look quite bad now but the game is 16 years old! (it was about 94/95 when I played it and it looked great to me)