Transport Tycoon, which I’ve spent an insane amount of time playing, as well as roller coaster tycoon.

Such incredibly fun games.

I think rollercoaster tycoon? not sure though

RollerCoaster Tycoon. The Gold edition is still worth playing today if you aren’t old enough to have the privilege of playing it in your childhood. (There’s a Android port too.) Way better than Planet Coaster.

RCT2 isn’t worth playing, though. Has much less content. The real life theme parks are cool, though.

RCT 3 was redesigned from scratch and is in 3D, which means that you can ride your creations for the first time in the series. Good for it’s time though at this point people would argue that you should just play Planet Coaster instead.

Transport Tycoon and RollarCoaster Tycoon (1 & 2)

He also wrote the PC ports of Elite 1 and 2, which were amongst the most innovative and technically complex games of their time.