I loved that you're encouraged to mix different types of units together: in the Ancient era, Archers/Spearmen/Catapults; in the early Middle Ages, Longbowmen/Musketmen/Trebuchets (Civ 4 was also really fun, but the rock-paper-scissors of "Macemen start out with bonuses against other melee units" "an experienced mounted unit can earn a bonus against gunpowder units" felt too messy to accomplish the same thing)
I loved the music: I've spent hours of homework time listening to the Ancient Era theme
(I can't remember any music that I loved from Civ 4)
... How could I forget about Baba Yetu?
Baba Yetu was beautiful.
I loved the sharp yet minimalist visual aesthetic (Civ 4 visuals were more detailed and more fun to look at stills of, but not as much fun to watch actual games of)
I loved that the different decisions from one game to the next make each game feel different (every time I played Civ 4, it felt like I was trying to do the same thing even when I tried doing it as a different nation)
I loved that all of the information is easy to keep track of (Tech Tree, anyone?)
I loved how quickly you could change to a government that let you pay to finish projects in one turn (in Civ 4, you either had to get the Pyramids first or wait until really late in the game)
),not V or VI...,for MGL,advisors and more.
The only games I have time for these days are the GOTMs, and here you definitely need a lot of warfare to get a good score... 
