The best of the best. Being the cream of the crop is being the best of something, it ranges from sports to school, to just being awesome. If someone says your cream of the crop, your better, smarter, sexier, more athletic, and just cooler then everyone else.
KU: I feel so bad since he broke up with me!
AP: Don't worry about you two breaking up, your the Cream of the Crop! Your the Best
there is! You don't need him.