horses for me primarily. They have been describes as passionate and brave, and they have have been able to succeed where others thought they would fail. they are a clan of diversity in every sense of the word. Their leaders come from every branch of the touman (almost), politically dynamic, and they really are the one clan that you get to use all of the clan toys available in a regular game, assuming you like to make fluffy units. They have some really cool characters like mad malavai, james cobb, temuchin amirault, among other minor characters.
Their galaxies are just as diverse, from being premier units that uphold crusader honor, to bottom of the barrel rebels. their clusters can be just as interesting, as there are a good mixture of elemental, mech and aero heavy clusters.
within the clan cooperation is not just mandatory, its something that is deeply ingrained in their culture, and can be seen since their founding, and be seen through some of their unique rituals like the branding ritual, where it's required to complete the task. I personally like the idea of a place where everyone has their place, and are respected for it.
By the time of the DA they have developed an interesting way of life since the advent of the firehorse galaxy, as well as the various castes playing sports together.
I've always like the quote that i use in my sig, and i think it helps describe parts of the horses well:
"Warriors, not war machines, are the backbone of the Hell's Horses. While others worship the BattleMech as the ultimate weapon, the men and women of this Clan see even this awesome piece of technology as the tool it is. We have held to this philosophy since the days of our first Khan, who knew that the value of the common soldier far outstripped the brute force of the BattleMech. It is one reason our Clan possesses fewer mechs than most, and has led many to underestimate our fierceness and courage. Our survival against all challengers when others have fallen proves the folly of such arrogance, and testifies to the wisdom of our founders."
- saKhan Tanya Delaurel
Recently however, shocka has been showing me the virtue of clan snow raven, particularly since i've been into the raven alliance since learning about them, and i like the clan periphery hybrid. The other raven fans have pretty much covered why i have come to love the ravens though.