I've "heard" Geddy Lee with Rush and "caught" one of McCartney's tours and therefore consider myself lucky since they're my favorites. BUT... by virtue of being something like 15 feet away from him during his performance, I'd have to say the best I've actually "seen" is Mark King with Level 42.
I swear that when he was slapping and popping, it looked like he was poping the string about a foot off the fingerboard!
I swear that when he was slapping and popping, it looked like he was poping the string about a foot off the fingerboard!