Civ V is the definite Civ game for me. It was actually one of the first games I've ever played on PC as it came free with the laptop I bought, the greatest gift of mankind. Ultimately, I've shelved the Civ series for paradox and 4X games in general, but it holds a special place in my heart.

This was my second Civilization game (first being Civ VI with no DLC) and this game just clicked for me.