TwoSix
The Year of the TwoSix
The change from Civ4's squares and stacking armies to Civ5's hexes and one unit per tile are pretty akin to the change from TSR AD&D to WotC "d20" D&D, I would agree.First 3 or 4 civs were evolutions from each other. CivV inwards are basically reimaginings.
Civ4 generally considered the best 1. I like 3 and SMAC myself.


