Changes from day to day.
Geddy is probably always in one of the top spots - he always sounds like him - it's the hands.
I forget the cat's name, but the bass tone on all the Our Lady Peace's albums has been phenomenal. I don't know how much of this is the producer, how much is the sadowsky, and how much is him. You may or may not like the band, but they all have great tone.
Victor Wooten always seems to have great tone, and once again, it's all in the hands. I love his tone when he's not being "flashy" the best. He always seems to have so much control over each note - each one has the right tone (and it changes from note to note) and the right volume. It makes me realize how sloppy i am at times.