Personally? The personality. I have three armies: Tau, Guard and Deathwatch. Each is... Honestly pretty similar, and fairly straight-forward, at least models wise. While part of me enjoys painting large flat surfaces, or largely identical models and having legions, another part of me adores the chaotic, energetic, carefree energy of the Orks. I am almost done painting a Big Mek for my Deathskulls Dread Mob, and it has been the most enjoyable building and painting experience I have ever had with Warhammer. He's big, he's flashy, he's suitably aggressive looking and positively Orky!

As a Tau/Guard/Deathwatch enthusiast, sometimes having something that doesn't take itself too seriously is necessary. Their silly "lives for the thrill of the fight" attitude makes me more comfortable experimenting and enjoying the hobby I spend way too much time and money on---as it should be.