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.
Honestly, looking at how modern game development studios handle remakes, I wouldn't want them anywhere near any of my beloved games. I haven't played a single remake in the last 20 years where I felt like the studio that made it knocked it out of the park.
Also, I strongly believe good games should not be remade, and only remastered/ "deluxe remastered" (where even if the game is remade, its a 1:1 faithful recreation with additional features and gameplay mechanics being optional). Remake the games that weren't great, give them another chance at big success.
Sonic 2006
the XenoSaga games (don't @ me XS fans, you know the combat and boss design in those games were terrible, 1 had DOMO Carrier, Tiamat, and whatever was going on in Song of Nephilim)