To the opposite end of the bass solos being discussed in another thread, what about simple and great basslines? Here's a clip of Sheryl Crow with Eric Clapton playing her "My Favorite Mistake":
http://www.youtube.com/watch?v=bpYL1ZTSnSA
IMO, this is a simple and great bassline. I love the fat tone she gets from the Ray. By the way, how petite is Sheryl? That Ray looks massive on her!
What are some other basslines that fit in this category?