Kim Deal, buddy. Simple, but very melodic and I believe she was in large part responsible for saving the Pixies from being completely over-the-top grungey-evil sounding.
Off the topic of females:
Flea
Tim Commerford (forgot spelling)
John Deacon
The cat from The Who was pretty good, although I'm not a big Who fan.
And I wouldn't call Matt Sharp an amazing bass player, but his work on Pinkerton sounRAB pretty cool to me.