I don't see it here so I will mention Battle for Wesnoth. Which is a totally free TBS game that has been around for quite some time and is still being updated.
Yes. Great mention. I don't see how I or anyone else forgot to mention that.
I haven't played it as much as I would like, but I bought it from the Google Play store for my Android device, only later to find out it is distributed for free. BeamDog hosts it on their site, I didn't know there were other outlets for it on PC. Thanks for the info.