The best and worst flight simulator in history is 10 years old. Official US release was October 10th 2006.
I can still remember how blown away I was when I had my first flight over Friday Harbour, and all the frustration I had in the following years trying to make it look even better. Despite all the technical problems FSX was a commercial success and laid the foundation for Flight, FSX-SE and Prepar3D which is my current simulator of choice.
What better way to walk down memory lane than look at this video (first video I saw of FSX) and listen to Hal Bryan (Former FS Community Evangelist, and part of the FS team since the late 1990s) on the FSElite podcast: