For me it was Terraria, Satisfactory, Tetris Effect Master Mode, Minecraft with Mekanism mod & CSGO / CS2 (almost 2000 hours in CS alone).
Edit: There are so many answers that I might only reply if I have something interesting to say. I will read all of your answers though. 🙂
Edit 2: It has become too much for me and I have to disable notifications. Thank you for the massive response and please continue to discuss with everyone here. ❤️ 🫡
RTS games for me, particularly WarZone-2100 & Earth-2150.
The fact that you get a base of operations to return to & has Picture-in-picture mode is a unique thing
Have you tried Beyond All Reason?
No, but played supreme commander
Awesome game!