Well first off you can't transfer music from your iPod to iTunes, only the other direction.
Second, why do you need a Top 5 list when one program that works is all you really need to accomplish such a simple task. YanniDepp made the correct suggestion as well, you won't find a better program than Senuti for this. Just select the songs you want, click Transfer and they're transferred to your computer and automatically added to iTunes.
Well, you can transfer purchased items from an iPod to iTunes. Just right-click on the iPod and select "Transfer Purchases". If it is an item that requires authorization (video, app, audiobook, or old protected music,) you'll need to authorize it.
Senuti. You have to pay for it now, but the older, free version is here: http://wstein.org/senuti/
Since the older version was GPL, there's no restrictions on sharing it like this. I really wonder who actually buys the new version.