When you think back to the people you've most enjoyed playing with, where they people who had already played a bit before you met them, or were they newbies before you met them? If they were brand new, were they your first group, or part of your first group? (That is, when you were new too?)
This is a less important question, but what about the people you've least enjoyed playing with?
(A somewhat tangential additional question: If you'd rather play with new folks than old hands, do you like playing with new people just for that new kid enthusiasm? Or do you like new people, but like them even better after they've played with you for a while?)