Do you mean which game do you think should have a remake of it released?
Hmm, that's a toss up.
Jedi Knight redone with better graphics and dedicated servers support would be cool.
But I'd also like to see Dark Forces with d3d support, mouse look, and other improvements (like Doom source ports have seen recently).
Now that I think about it, the Rebel Assault games redone for DVD-ROM (with MUCH higher quality video and sound) would be pretty neat (to say nothing of something like 'Behind the Magic' or 'Insider's Guide' on DVD-ROM). Or DVD-Video for that matter...
LEC has had a tendancy (and I don't blame them) to release games, but usually just by throwing them in a new box. On other occasions they'll throw out a patch to add some value to the game (like Outlaws or XvT). But some remakes would definately be cool, given today's technology.