The first not-explicitly-for-kids game I ever owned growing up was, weirdly, Colonization (I got it as a Christmas present -- I think my folks thought it would be educational, and, well, it was, sort of). I played it constantly, always on easy, always on the New World map.
In many respects, it's similar to Civ, but it differs in that there's an additional economic/worker management side, and there's a really satisfying loop in there of: distribute colonists to jobs -> farm cash crops -> make finished goods out of crops -> ship goods to Europe for sale -> buy new colonists/raw materials -> ship to colony (-> shift what crops are being produced so as to not flood the European market and drive the prices down, educate/acquire colonists as needed for new production) -> goto start
There's something very satisfying about that specific loop that I haven't really found in a lot of games. That latest QL got me thinking I should check out the Anno games sometime since they're probably the closest I've seen lately. I'm afraid the city building parts would get in the way for me though (in Colonization, buildings just have a slot on the colony screen, and if you need higher production, your options are to either upgrade a building or just assign more/more specialized colonists to it).
(Colonization is a great, weird game and if I was still in school and had time to research I could write a heck of a paper on its bonkers interpretation of history.)
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