None of these are deal breakers, just some general likes/dislikes. 

VERY TASTY:

• Tusks, fangs, interesting teeth
• Loose/wrinkled skin, chunky dog like lips
• Armour, weaponry
• Mechanical/robotic or otherwise enhanced beasties
• Anything to do with biology, medical nonsense
• Neat colour combos

Not my cup of tea:

• Overwhelmingly saturated/neon designs
• Non natural pupils (stars, hearts etc.)
• Humans/furry humanoids
• Tiny wings on large flying creatures
• Less realistic/anatomically accurate styles such as chibi
• Obscenely detailed and intricate designs
• Styled, human like hair on the head (manes etc are fine!)
• Reused bases