Burning Rangers would benefit greatly from a remake. The game already plays and sounds great, but updated visuals and more stages to would really give it the needed boost. Also can you imagine this game with cooperative multiplayer?!
I second the GunValkyrie suggestion. Brilliant game, brought down by tough, non-customizable controls. Also, add cooperative multiplayer.
Another game I'd like remade would be a full 3d, coop tps/fps, Gunstar Heroes.