HereForTheBeer: I've long held the opinion that RT was a pioneering title for the industry, combining economics and sandbox. RT2 brought in much better graphics, simplified some of the mechanics of working the tracks, and made it overall a better game. RT3 just built on that even more. Great series and I'd love to see it arrive here at gOg.
Speaking of RT3 building upon RT2, the one thing I best remember is how much they improved RT3's editor. Before, in RT2, if you wanted to have any sort of scripted events, you needed to have either memorized the included editor scripting language manual or printed out said manual. In RT3, however, all of the scripting commands were conveniently contained inside block-like constructs, and you could easily add, remove, modify, and change the execution order of the commands. It was truly a night-and-day change, and it actually allowed my then-young mind to quickly grasp how to build a scripted scenario - complete with win conditions! (Admittedly, my first conditions-based scenario consisted of nothing more than choosing the proper candidate in an election in order to determine whether you won or lost. :/ )