Obligatory Final Fantasy VII shout-out. The gameplay has aged really well, but the visuals have not. Why the remake decided to rebuild the entire gameplay system from scratch, I will never know.
Also, the entire Ultima series, up through the VII duology (and Underworld games). Update the sprites to around the level of the Final Fantasy PSP remakes, add some actual sprite animations to I-V (and some more animations to VI), and rebuild the interface to modern levels of intuitiveness and convenience. They're still all fantastic games, but it's really hard to get into the series when the actual play of them is so very dated.
Also, the entire Ultima series, up through the VII duology (and Underworld games). Update the sprites to around the level of the Final Fantasy PSP remakes, add some actual sprite animations to I-V (and some more animations to VI), and rebuild the interface to modern levels of intuitiveness and convenience. They're still all fantastic games, but it's really hard to get into the series when the actual play of them is so very dated.