X-wing vs Tie Fighter wasn't even that great of a game when compared to Tie Fighter itself, which was just plain amazing. Tie Fighter wasn't just an amazing game, but had one of the best stories of any game ever.
I would like to see Baldur's Gate remade for real, sure. System Shock definitely. The first Deus Ex definitely.
Chrono Trigger is probably my favorite game of all time but I wouldn't want to see it remade ever, it holds up on its own. FF6 could be remade but SquareEnix could not afford to do it justice. It would probably take the resources of 5 modern FF games to remake it as a fully modern game while keeping the huge open world aspect and other gameplay elements the same.
I'm pretty sure there IS a Rise of the Triad remake in the works, but that game was terrible anyway. Awesomely terrible but still terrible. A Hexen remake would be awesome but I think if you tried to remake it you would end up just making a much better game. That game really wasn't that good so much as it was a unique idea that could be done so much better today.
Homeworld deserves a modern remake or a spiritual successor so badly that it's not even funny. Syndicate remake would be great. X-com was basically remade, and came out wonderfully, but a mod to make it into a truer remake would certainly be welcome.
I don't even know if remaking Daggerfall would count as a remake, since that game never really worked the first time. I've never seen a game with more gamebreaking bugs, I'm shocked anyone ever finished it.
PS: Fuck, an Alpha Centari remake is still a must. Molyneux is making a next-gen Populus style game so maybe that will also be good.