I was browsing through the games boxes in the store back in the day, and bumped onto two titles that looked interesting in the empire building genre: Europa Universalis and Imperialism. That was later followed by HoI, EU2, HoI2, Victoria and CK. Of all these, I think I've played EU2 the most, by far. Skipped the EU3/HoI3 stage, as at the time my PC hardware wasn't powerful enough to run them on. Right now I've EU4, HoI4 and Stellaris in Steam.
In fact, the Paradox games were the one and only reason I even have a Steam account
In fact, the Paradox games were the one and only reason I even have a Steam account