Maybe I'm the strange one out, but I just upgraded from a 1Gb shuffle to a nano 4GB Ipod, and while my music collection is about 5 or 6 GB, in practice I don't want to hear everything all the time.
I don't even use the 4Gb for now.
30 or 60 Gb is definitely overkill for me - I wouldn't know what to listen for first.
If you don't want the video, I would go for the nano 4 GB. More than enough to have some variety, plus you get to choose what you want to hear, which is damn hard to do on even a 1Gb shuffle.
A.