FireRed is my personal favorite Pokemon game. People will moan at Kanto in new games nowadays, and I can't blame them, but I genuinely love the region design and how different it is from later games, and all of the Pokemon in it are iconic for very good reason. FRLG are the best way to play Kanto in the familiar Pokemon formula, with the post-game Sevii Islands that weren't in the original Red and Blue and aren't in any future games, and very visually pleasing 2D graphics that defined Pokemon for over a decade.
I'd love to see a native PC rerelease of this and other older Nintendo games on GOG.