@RD -- I'm a big fan of Reverend Al's early-70s stuff, which is the period that Greatest Hits compilation encompasses. Probably a good idea to get those albums first.
Since you mention Motown, thought I'd just mention that I'm a HUGE fan of James Jamerson who was the bassist for TONS of Motown stuff back then. He seemed to create extremely groovy basslines out of thin air that didn't dominate a song. But once you notice how his basslines dance beneath upon rhythm, you can't help but be mesmerized by them!
Some examples:
Jackson 5 - Darling Dear:
Marvin Gaye - Ain't That Peculiar:
Stevie Wonder - I Was Made To Love Her:
The Four Tops - Bernadette:
