I know that remakes and remasters are contentious, but let's pretend whatever game in question you're thinking of is handled with the utmost care by your favourite devs and they absolutely nail it.
Mine would be Shadow of Memories (called Shadow of Destiny in North America). It's legitimately one of my favourite games of all time but it kinda flew under the radar and I haven't met many people who know of it let alone played it. Seeing it get modern graphics, maybe some expanded mechanics, would be soooo cool.
I’d love to see Ocarina of Time and Majoras Mask get a full remade release, bundled together into one game ideally. Sure we got the 3ds remakes but I wanna see it back on home consoles, like tp and ww HD.
There is a GitHub project working on a recompilation of both of these for PC. They've got Majora's Mask working and are working on OoT. Looks beautiful, runs buttery smooth, and has custom controls with a free camera.