For me the oldest save file I have is for May 12th, 2007 for my Pokemon Diamond version. My GC had older saves (only as far back as 2006) but my memory card got corrupted a few years back ;~;

My copies of the Dragon Warrior Series from NES still work. Those watch batteries are real soldiers.

Probably my dear Pokemon LeafGreen save. Probably from 2005, but I don't exactly remember the year, it's been so long.

Toughie. I would guess my Rayman save file from ~1999.

My Gran Turismo 2 save goes back to about 2002 or so, I had other saves on Gamecube which were about as old but they corrupted years ago.

Legend of Zelda: Ocarina of Time. I think it was back in 1999 or 2000.

Early PS3 stuff. Resistance, Motorstorm. All from 2007. I Think technically it's Heavenly Sword from August 2007.

Wouldnt have a clue, would assume its the oldest save on my PS2 Memory Card but I deleted shit off of that all the time to make room for new games so I would assume 06 or 07. Probably my FFX save file but Im not breaking out my PS2 to check.

I have a couple of old saves from SimCity 2000 and SimTower, so those are halfway through the '90s. I'd need to check to see which one is the actual oldest one. Consolewise probably Mario 64 from '97 or some Gameboy game.

Not sure. Probably something on Gameboy Color like Oracle of Ages or Kirby Tilt n' Tumble. So 15+ years. My Pokemon Silver save file is gone because the battery in the cartridge crapped out.