I haven't read all the responses and this may have already been mentioned.
Paul McCartney is one of the tastiest bass players around (listen to his lines on Penny Lane). I would recommend learning his bass lines.
Check out this book,
The Beatles Complete Scores, which contains 1,136 pages of transcriptions of every instrument for every song they recorded (including bass tab). The only down side of this book is the print is rather small and at times I have to grab a magnifying glass.