Hi,
I understand your problem, I was confused myself a few weeks ago. First of all, what you need to understand is:
iPod of the 5th generation = iPod 5.5 = iPod Video
iPod of the 6th generation = iPod 6 = iPod classic
now, the difference is basically: the iPod classic is just newer than the video. the classic came out a few weeks ago. It has a completly new Interface, games and has a bigger hard drive (80GB (250$) or 160GB (350$)). Also it's a little smaller than the old iPod video.
but there are some downsides when you buy the classic: first of all it's still new, so there are some bugs. just check the forum to find out about them. but hopefully, apple has them fixed by a firmware update in a few days. secondly it seems that the classic has some faulty products in the stores. a friend of mine bought one yesterday and it wouldn't connect to the computer. Went back to the store, got a new one that worked perfectly fine. There are more stories like this here on the forum.
For a good comparison of the old and new interface check
http://www.youtube.com/watch?v=V6MmHF0C5Gc
so ... that's it. the classic is just the successor of the video. but it still has some bugs. most of them will be fixed, but for example a lot of people are complaining about that the classics sound is not as good as the videos. if that would be a hardware problem it would never be fixed. you have to decide yourself what to buy.
Message was edited by: m8an