AOE2 was the best. Civ 5 is my favorite Civ game and I think overall the best in the series. 2 was great - it introduced a different map style and enhanced features for the first time, but the gameplay was a bit clunky.
I only played AoE 1 back in the day. So I'm playing Definitive Edition of it. Compared to the original, the graphics are nicer and you can zoom way in/out plus new map types, new civs, etc.
I'm pretty sure they just released Age of Kings Definitive Edition too, so you're good.