I tend to vary my way of playing and my game targets greatly depending on the alignment, so, I would say:
GOOD: Malakim. The adaptative trait is just too good to let it pass. And I'm lazy enough to enjoy not *having* to build the damn monoliths, and hate paying for them also so... Also, their starting mana selection is also superb. And I love golden armours. Runner up: Elohim... I hate the AC and love to be able to decrease it to 0, permanently. No matter how expansive I feel.
NEUTRAL: Grigori. Oh, the joys of forgetting the worries about religion (ok, forgetting the benefits too, that's the tough part of the deal). Their enchantment mana helps them now to recover a bit from their loss in the happiness way. Again, while I have to build monoliths, at least I don't have to pay for them. And heroes are the blast. Specially if you save all of them for spellcasting. Runner up: Amurites. Cause I love the magic system.
EVIL: Balseraphs. And more specifically the lovely crazy Perpentach. I love having 3 traits at all time, and I don't mind too much which they are... it's always fun to make a rush for new units when you have a trait that would give them an initial improvement, and sometimes... well, I once got agressive+raiders+defensive, which produced very fine units from the start. Loki is *incredibly* good in the eary game, helping you tons to have the initial area you need for your starting empire, when you are not strong or mobile enough to take care of your neighbours (unless you are unlucky enough to start surrounded by creative nations). Runner Up: Calabim. Love the vampiric theme, and the so, so many special combat mechanics available to them.