This is the very reason I'm in no hurry to lvl mine. I'll level my breed#4 snow cub first. The nightsaber cub is the best cat, IMO. More health and power and even though she's slower than the cheetah cub she's still faster than most of what she's put against and can deal out serious damage. They are a tcg pet but the cards go for less than $10 on ebay.
As far as looks though the cheetah cubs are freakin' adorable. My crazy cat lady goal is to have all of the cubs available in game leveled to 25 eventually!