We started to play a couple of team battles vs the AI to familarize us with the game. I got my hero killed more times than he, so I suppose he's your man.
I'm quite fond of Fey IIRC. Last game I tried undead. I had forgot that you turn skels into whights etc. I like that feature. I also got confused about unit lvls, until I realized that shadows drain xp. I could not fathom why I had a lvl 11 shadow running around. Turned out he ate pixies for breakfast (and a level each time). Then came the centaur Titan and destroyed my base
Dark dwarves should be fun, but are a bit boring, as they have less variance in their troops.
Elves and their whisps are also fun.
I also like leveling up my heroes, but they soon become a tiny bit too powerful
Pity the game doesn't scale with hero level.
Cave worlds are more interesting strategically, with chokepoints etc.