I have both a 20GB iPod, and an iPod Mini and I love them both. iTunes is (in my opinion) the nicest jukebox/music management software I've ever used, the iTunes music store is great (for music and audiobooks), and the integreation with the iPod is seamless.
I am (unfortunately) by no means a "price sensisitve" gadget shopper ("it's cool! I want it, and I want it NOW!"), so I am willing to pay a premium for small size, and a superior user interface. I think that is one aspect the iPod really shines in, its user interface. It's pleasant and brainless to use.
Chris