The first PC game I can remember playing is Chris Sawyer's original Rollercoaster Tycoon. This was probably back in the early 2000's when I was still in late grade school/middle school time, and I have very, very fond memories of that time. I remember playing it all the time and wanting to get the next "expansion pack" or game that added more rides and parks to play, but given that I was so young, I never had the money to buy it.
It's interesting to see how things change when you grow up, and I bought the entire Rollercoaster Tycoon package for a good deal on Steam, and I finally have all of the expansion packs, meaning I can now play the parks that I never got to play as a kid. Very nostalgic, and it feels great too, haha