I have to list my top 5 favorites, because I like so many. Again, these are my top 5 favorite bass players, not my top 5 best bass players.
#1, James Jamerson - His grooves, tone, and musicality were just out of this world, and still unparalleled today. He was just a musical genius, and I can't stop listening to his bass lines. The fact that he played everything using only one finger to pluck the strings makes his playing that much more impressive. His bass lines were so melodic, yet he never lost that bottom-end groove in a song.
#2, Stefan Lessard - I love Dave Matthews Band, and I love the way Stefan's tone and playing style fits in with the music and the rest of the band. He's a versatile player, and he knows when it's the right time to lay back and when it's the right time to shine. That's a true musician.
#3, Francis "Rocco" Prestia - I'm a big Tower of Power fan, and I never cease to be amazed when listening to Rocco's bass lines. Nobody does finger-style funk better than Rocco. His bass lines have so much heart and soul in them. And when you pair him with David Garibaldi on drums, it's one of the best rhythm sections in history.
#4, Pino Palladino - He's such a well-rounded bassist. Pino says that James Jamerson is one of his biggest influences, and you can really tell. He plays like a modern-day James Jamerson, which is NEVER a bad thing. Palladino has played and recorded with SO many people, but I love hearing him play with the John Mayer Trio the most. I love his tone, and his bass lines are quite impressive. His Fender signature bass is really cool too.
#5, Tal Wilkenfeld - I only discovered Tal Wilkenfeld earlier this year. But since hearing and seeing her play the first time, I've been blown away by her talent. Her playing is so smooth and musical. And her tone may be my favorite out of every bassist I know. I'm very impressed with her level of musicianship, because she knows exactly what to play and when to play it. That's not always easy to find. And she's definitely not one of those bassists who always seem to play the same thing.
Almost making my top 5... Victor Wooten, John Paul Jones, and Michael Anthony.
Tie. 
