For newer games, I guess some indies would be nice like Journey, Flower, Unfinished Swan. Seeing those games remade & upgraded in 4K resolution would be mind-blowing. And the original Mirror's Edge.
But I really feel that it should be at least 2 generations (PS2/Xbox or older) before something should be considered for a remake, the older the better.
#1 Would be Final Fantasy VI. A real remake and not just some cutscenes tacked on. (Willing to bet Adam will be with me on this one)
Others would be:
Any of the Final Fantasy Legends/Legend of Manas
Crazy Taxi
Jet Set Radio
Rumble Roses - Come on, you know you want this!