Transport Tycoon Deluxe was amazing, as a kid it took me so long to understand how the game worked (being from a non-English speaking country it was mostly trial and error) but once i understood i spent hours on it every day. I still remember the excitement of completing my first campaign, and getting the pop-up message in 2050 that I won the game, such a wonderful feeling.

There is an open source remake of it called OpenTTD available on steam, which is the same game with quality of life improvements, better graphics (as far as pixel style games go), and lots of customizability options that I still play to this day, it still is one of my favourite games of all time