Joe Buck revealed in a recent interview with Graham Bensinger that his homerun king is Hank Aaron.  He also told a story about the time he met Barry Bonds.

Met him might be a stretch, because Barry didn't shake is hand and said "so" when told who Buck was.  Buck might be a little salty about that meeting.

You think they would have run into each other at the secret meetings of the enormous head society.  I mean Bonds isn't a member anymore, but he was in the club at one point.