I don't care about remakes much, I would rather that they just released the originals and made new games instead.
I could be interested in something less drastic. Many old games suffer from really cumbersome control schemes that I don't enjoy much, so if someone were to hack them for more modern controls to make them more accessible that could potentially be pretty swell.
The first that I can think of is Omikron, which frustrates me a lot. Any old shooters without mouselook+strafe perhaps. Or Tomb Raiders?
This might make them way too easy, though.