My advice is, get the most storage you can afford. That being said, just because you have a lot of storage space doesn't mean you should waste it. iTunes Match is the key to making effecient use of your space. I have 40GB+ of music however I'm only using up 4GB of space on my iPad. iTunes Match basically gives all your idevices access to all your music in the cloud, and only downloads the music you want to play. My wife can access the same music library on her iPhone 5 and iPad mini, all while using very little space on any device. The service is $25 per year and well worth it. No more connecting to a laptop to transfer music and no more wasted space on any iDevice.
I'd also recommend getting an LTE version. The reason I say that is, the internet and an iPad go hand in hand. I have a 4th gen 64GB LTE iPad and love the fact that I can take it anywhere and always have access to the internet. You also have a built in GPS. Another great thing about an LTE enabled device is, if it gets stolen, I can remotely wipe it at any time.
I'd also highly recommend an app for all the movie collectors called "Movie Manager for iPad." I have over 700 blu-ray movies and this little app does a fantastic job of cataloging all my movies. It uses the iPad camera to let you quickly scan your movie into your library using UPC bar code. Now I can quickly browse my collection using my iPad.
And while you're at it, get an Apple TV. I use my iPad to stream music from my iPad to my Apple TV and it works flawlessly. Beautiful combination.Edited by LaoChe - 12/27/12 at 7:29am