There are literally thousands of great games that could be remade and remastered and i have no doubt they would find new audiences.
We've only had a few high-profile remakes that i can think of (GOW, Tomb Raider anniversary, Riddick, Perfect Dark, etc) but there are so many options and i have no idea why developers cant make them happen. My personal list of games that i would love to see remade and remastered in HD are :
Jonah Lomu Rugby
Shadow of the collosus
All classics in my opinion but if i want to play them i'd have to go out and buy a PS1/PS2/Dreamcast,etc. I would gladly part with my hard earned cash for these games if they were on XBLA, PSN or re-released for retail sale.