Though it's not his domain and is a one-off like Railroad Tycoon, I love the article on Sim City: http://www.filfre.net/2016/06/simcity-part-1-will-wrights-ci...
The history of the TRS-80, whose place in PC history I did not appreciate before reading: http://www.filfre.net/2011/06/the-trash-80-part-1/
There are many more interesting articles he lists on his own best-of list: http://www.filfre.net/hall-of-fame/