One of my all time favorite instrumental groups was the Ventures. One of the best bass guitarists in the business and, in my opinion, the best drummer too:
Well, it seems that there's a need to define "funky" right about now. Many mentioned are GREAT, SUPERB, and SPECTACULAR but they are a far cry from FUNKY.
And since it has been adopted by everybody's favorite (cough) radio talk show host, you'll probably hate this one, but it is still has a really funky bass line--by the Pretenders: