For me it’s Super Metroid. I have played Zero Mission, Fusion, Metroid: Samus Returns (3ds) and Metroid prime remaster, three of these games are remake/remaster. So you can see why I’m hesitant to start Super Metroid, I’m sure that game still holds up, but playing it with modern controls annd other bells and whistles would be more ideal.
I’ve never hold up a first play because of a potential remaster, especially not if it was not announced.
I have hold up a few replays when rumours of a remake are floating around though (like I did with Skyward Sword). I stopped a halfway through replay of Xenoblade Chronicles when they announced Definitive Edition. With how long XC games get if you try to do everything… Yeah.