Damn it hard too pick just one bass player I can't. the ones that have been mentioned like JPJ & John Entwistle & Les Claypool are obvious choices but Geezer, Billy Cox, Mel from Grand Funk Railroad,Paul McCartney,Chris Squire,Tommy Shannon,Phil Lynott & Steve Harris need mentioning also.
Sorry but with so many great bass players out there I can't. pick just one.
The bass player I jam with now is one of the best i've ever jammed with a true natural talent.
Too have a great bass player too jam with makes a drummers job a lot easier heck we make good guitar players sound better we just don't. tell them that LOL