Pong. Even though it was on a disc made by Atari, it could still be considered an emulation. Saying that, I did play it on the original Atari system back in the day and it was more a computer than a console (as in it had a keyboard, you could type and print with it and you had to copy out pages of code just to get games to run on it).
If that doesn't count, it's probably Populus. --- PC is the only place to play games at their true potential. 1080p/60fps standard, mods, FOV sliders and ultra graphics - all the while being fully upgradable
Oldest game that I still have physical copy of would either be King's Quest 5 or Battle Chess, but actual oldest game I've played would either be King's Quest 1 or Ultima 1 depending which version is on GOG