Rollercoaster Tycoon 2...
You create a Theme park of your dreams with tons of different rollercoasters and playing scenarios that range from easy to hard... It's one of my favorite games from my childhood, and i remember always playing the build your own six flags park as my favorite scenario and infernal views because i love building a theme park in volcanic lava lands with a industrial factory themed park there...
If you want to play that game. Go grab RCT2 from Steam or from GOG. And Download OpenRCT2, and if you have the first game from either from those stores, you can play RCT1 Scenarios with OpenRCT2 and they are more fun than RCT2's scenarios with the tools and improvements from the second game's mechanics...
The game aged well, and has always been my favorite PC games of all time...
