Beastmen are intimidating, savage and horny
Although they are dedicated to their cause the cause is chaotic and they dedicate themselves in a rather chaotic way.. Their aggressive nature (and battlefield tactics) appeal to me and to be honest, I think their (the whole race's) attitude towards all things impresses me somewhat..
On the other hand, I like Asrai, Asur and Tomb Kings for pretty much the opposite reasons
Asrai have some of the savageness of the Beastmen but the Tomb Kings and especially the High Elves seem totally detached from such distracting feelings. They protect order, their domains and their families/riches. They are civilized and they have a certain..finesse
The Beastmen still own them all, though