“The Cream of the Crop,”
(phrase)
The best or choicest of anything. Cream is the most concentrated, fattiest, most desirable part of a batch of milk, and it tends to rise to the top. So the idiom cream of the crop refers to the best part of a batch.
In example:
“You should join the Moonspear Trading Company. Among the many roleplaying guilds on Argent Dawn, they are truly the cream of the crop.”