I orderd the 3G with the full 64 because I remembered when I told myself that 20GB was fine on my computer, than 250GB, than 500GB. Now at home I have 4TB on my desktop and another 4 in backup externals. If you can afford it, always go for the most storage if you can't add it yourself. I'm not even going to put much music on it, only my favorites which is about 5GB out of 300G of songs on my MacPro. I love pictures so I'll put about 5k of them also. I have a ton of PDF and EPUB books and comics and magazines. After I load my ebooks and Zinio collection, I have National Geo, Natl Geo Traveler, Country Home, Elle, Esquire, MacWorld, Tatoo Magazine.....and comics Star Trek collection, MAD comics, Rolling Stone, Marvel, Archie...that's going to take up 20Gs. I'm going to have to rotate my favorite movies. I have ripped over 500 at about 2G each and way too many TV shows which I'll hold back on because of Hulu and the others but TRUE BLOOD is going on the Pad and some of my concert albums. My problem is I have a few hundred music videos, thank God they don't take up much space. I don't even want to think about my Disney Shorts collection or things like Ren & Stimpy, Invader Zim, etc.