*Mawlocs

Pfff difficult one really, Dark Eldar ftw but i like CE, SM, CSM, SoB, IG and Necrons a lot.
As a side note, Tau aren't socialists or communists, they reflect eastern philosophies on how society should be organized. If they truly were socialists they wouldn't have a caste system for example.

Hindu, perhaps? I admit, I know little of it, other than the fact it has a caste system.

Hindu? No no no no... Tau are japanese. It explains the manga-look as well as why they make such good sushi.

The Tau are a big combination of different parts of Asia just like the SM's and the IoM are a big combination of western influences.

Imperial Guard. They're a lot more powerful than most people think they are.

And also the reason why voice actors playing as Tau have a Japanese/Asian accent.

Renegades and Heretics! Specifically the first Vraks renegades list and the plague variant. Just great personalities!

Eldar, particularly wraith constructs because I need a LOT more of them, saving up for ghost warriors pack, it will be Christmas all over again!

Chaos Space Marines

Tyranids (even though I am a little dissapointed with the new codex... It may not suck, but I am still dissapointed)