Years ago I would have still been advocating a Wing Commander or Ultima revival, but now it's been so long since those series were relevant that I've sort of stopped giving a shit. That and a "re-booted" entry in the games would undoubtedly be a compromised mediocre imitation, with a dazzling engine and graphics, sure, but it would miss the magic of the original games. The miserable end Ultima endured was pretty ignominious, with the Ultima IX development hell and quarrel with EA debacle, but Wing Commander was pretty stellar to the end. They were about the only successful experiments in FMV gaming around.
An Arcanum or Vampire: The Masquerade sequel (connected to Bloodlines or an original) I'd die for, except I'd want it made by Troika. Otherwise it'd be too easy to foul up by dumbing down the mechanics, details, subtleties, and writing that stood out in those games. I would have preferred to play Black Isle Studios' Van Buren to Bethesda's Fallout 3. I would have preferred to play a hypothetical Looking Glass Studios' Thief 3 as well.
Alpha Centauri is still my favorite game of all time, though by this date even I admit it graphically needs an overhaul. As a testament to its design genius, that's about all it really needs, to be honest, aside from bug-cleaning. Some cleaner, more modern graphics while still retaining the dark and sinister isometric grit of the original Chiron (instead of the cartoony route the Civilization series has taken), while not being too resource-intensive to make it run efficiently on laptops, would be most welcome.
I'm really upset Headfirst Studios didn't get to develop the other two games in their planned Lovecraft trilogy after Call of Cthulhu: Dark Corners of the Earth.