It's either one of two.
Gemfire. A simplefied strategy game like Romance of the three kingdoms. It was on the SNES by Koei. We must of beaten that game over a couple hundred times from grandschool through JR High. With me playing it in highschool to.
Or Civ 2, which i played nearly every day for a year or two.
Third place is probably Front Mission 3. Since i've beat that game 4-6 times at about 30-50 hours a playthrough