I've owned several iPods, currently I mostly use a 1GB iPod shuffle. That's fine for me, like Neil I usually just upload my songs for the day. When I'm away for longer than just a couple of days I've got my old chunky iPod which holds 20GB (I think).

I don't really care too much about the mp3 quality on my iPod, usually I got the mp3's in 128kbps on it. I mainly listen to it in the train, on the plane, while riding my bike, while exercising etc - circumstances with too many noises around to hear any differences in quality very well anyway.