SoulCalibur 3 with better balance (the arcade version is much better in this regard), modern day graphics, SC5/6-era Creation Suite, and a great online system would be amazing
Would like to see modern versions of Star Wars Rouge Squadron and Star Wars Racer from the N64 too
Some games like Saints Row 1&2, Morrowind, Oblivion, could use a graphics facelift but otherwise don't need a remake, just a remaster (though I wouldn't mind a SR1 remake tbh). Same with Diablo II, it just needs a remaster, there doesn't really need to be anything else added.