I want to get a video iPod, but I don't know which one to get. I want to spend $250 or less and I would consider a refurb unit. I want to load a bunch of music but still have room to put a DVD or some TV shows on it as well. I use a PC right now, but plan on moving over to an iMac at some point in the next year. It looks like a 30GB iPod might be large enough, but I have no real idea how much space a DVD might take up or say episodes of The Office. Also, is there enough of a difference between Gen 4 and Gen 5 that I should stick to a new unit rather than a refurb? I've been reading the Apple site and I am unclear what the differences are between Gen 4 and 5 other than 5 is thinner and you can now get an 80GB.