I have recently been on the market to replace my 80 gigs ipod for a new one. I use my ipod principally to listen to podcasts and as an external hard-drive.
I have been surprised by a discontinuity in terms of hard drive space.
The Shuffle and itouch range between 8 and 32 gigs. The next data point is 120 gigs for the ipod classic.
I have put all the pricing (from apple’s US store) into a spreadsheet and compared prices and features. If you are looking to maximise dollars spent per gigabyte, then the “classic” is by far your best option.
Click on image below to dowload the pdf chart.