I have spent a lot of time and energy learning bass. Rush is my all time favorite band. Geddy is a unique player, and at one time or other I have learned almost every Rush song. Great player.
Learned a lot of Yes too Chris Squire was a fine player.
Learned lots of Who songs- Entwhistle was the original aggressive bassist in a rock setting.
Seriously though, if we are talking the best rock bassist the conversation really probably stops with Billy Sheehan. He could take the aforementioned guys to the woodshed from a purely chops standpoint.
Then let's not forget the non rock/ jazz/ fusions guys. Stanley Clarke, Jaco Pastorious, Michael Manring, Bunny Brunel, Dave Larue, Stu Hamm. I could go on.
