Okay the gender of Slaanesh has been discussed to death, but there is another chaos power that is surely interesting to discuss:

Tzeentch is most definitely female, immagine how a male could be so sneaky, underhanded, manipulative, greedy, amibitious, etc. etc. All tradmearks of the new age emanicipated female.
Also she uses her minions only as long as they provide some use then they are discard like broken or useless toys. She demands abosulte loaylty but she frowns if you expect the same from her.

These are just my preliminary "findings" i will add more with time.

P.S. This thread IS NOT meant to be about gender bashing or sexual discrimination of any kind, it is just a jest on human gender stereotypes, that the two sexes overimposed on each other. With this in mind carry on the debate in cynical yet as kind as possible tones!