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. ❤️ 🫡
Dwarf Fortress.
I would constantly miss meals and sleep to keep playing. Sometimes multiple days at a time. Went like 36 hours without eating or sleeping until someone popped into vent and asked what I was up to and after hearing me talk about the Fortress the asked when the last time I ate was…