I recently played an amazing DOS game where you have your country and you can declare war or peace with other ones, and i really enjoyed it. Growing up one of my favorite DOS games was Gobliiins 3, such cool memories!
TIE Fighter! It's the reason I really got into gaming, PC gaming specifically. Mario on NES and such were fun, but TIE Fighter was the first game I'd spend all day at school thinking about and then spend all afternoon and all weekend playing. It's on Steam and GOG and has aged really well.
Your comment totally gave me a flashback. I was always fascinated by the huge ships in the X-Wing/TIE Fighter games, and I spent soooo much time daydreaming about those games in elementary school. No internet required, just imagination!