Consoles
Nintendo Entertainment System: Super Mario Bros.
Super Nintendo: This one is really tough, but I'll have to give it to Super Mario World. My other consideration was Doom, which I originally played on the SNES (and as I understand it, this is the worst version of it).
Sega Genesis: I count these two as one game, so I'll say Sonic 3 and Knuckles
Nintendo 64: Perfect Dark
Gamecube: This one is the toughest one of all, because it's between Paper Mario: The Thousand-Year Door and Metroid Prime, but I'll have to go with the latter that is Prime. A close third would be Resident Evil Remake
Playstation 2: Final Fantasy X
Playstation 3: Dead Space
Playstation 4: Alien: Isolation
Switch: Just got this console and haven't played much of it, therefore no verdict
Handhelds
Gameboy: Metroid 2: Return of Samus
Gameboy Color: Pokemon Silver
Gameboy Advance: Metroid Fusion
Nintendo DS: Pokemon Diamond
Nintendo 3DS: Pokemon Alpha Sapphire
Nintendo Entertainment System: Super Mario Bros.
Super Nintendo: This one is really tough, but I'll have to give it to Super Mario World. My other consideration was Doom, which I originally played on the SNES (and as I understand it, this is the worst version of it).
Sega Genesis: I count these two as one game, so I'll say Sonic 3 and Knuckles
Nintendo 64: Perfect Dark
Gamecube: This one is the toughest one of all, because it's between Paper Mario: The Thousand-Year Door and Metroid Prime, but I'll have to go with the latter that is Prime. A close third would be Resident Evil Remake
Playstation 2: Final Fantasy X
Playstation 3: Dead Space
Playstation 4: Alien: Isolation
Switch: Just got this console and haven't played much of it, therefore no verdict
Handhelds
Gameboy: Metroid 2: Return of Samus
Gameboy Color: Pokemon Silver
Gameboy Advance: Metroid Fusion
Nintendo DS: Pokemon Diamond
Nintendo 3DS: Pokemon Alpha Sapphire