Varies... question is rather silly... very moment when person says someone is the best, chances are high that they are already lusting for another babe... so that's about being the best...
I like different babes for different reasons or maybe more accurately, I like many babes because they are different from the very first place. Thought that doesn't remove the fact that I do have my standards, tastes and other factors... All those naughty and sexually arousing things have more importance afterwards...