Your nostalgic games - why?

Rainbow Six : Vegas 1

My neighbor and I used to play it when we were kids. I bought it for Steam just last month, and Christ, did this game not age well!

It was very interesting coming back after 10+ years to see the state of the game.

Secondly, Unturned...

1300+ hours, a game I spent playing with the same person, almost every single hour was with the same dude. Good times. Still have it installed, but it's not worth playing.

Grand Theft Auto : IV

Let's be real for a second, GTA 4 is amazing, old and still relevant.