have you all checked your pc's that there are no known viruses? I have run ipod for years and years on BOTH PC and Mac, and it was ipod that convinced me to buy my first mac.
I can understand your frustration though with a product that promises a dream and that does not happen:
1) I am on my FOURTH (NEW!! 160gb) ipod ("classic"), as I had nothing but problems with the previous models (all since Jan 2008!!). Apple willingly exchanged the ipods each time. Now, whilst running itunes 7.7.1, I do NOT !! install the latest ipod firmware update (for mac that is 1.1.2), as each time, I installed it, I had massive sync problems. so I have declined that update, and my ipod is running perfectly now.
2) the new ipods are a bit fickly, as the technology that enables them to be such a big harddive (there a 1 Tb drives now that are the size of the old 2.3gB drives!) into such a thin shell. Dropping is not a good a idea. The older, chunkier ones were much sturdier in my books, but if you want video you need the new ones.
3) If your itunes library is uncorrupted and fully working, then you NEVER loose your music, as ipod is designed as a read only device that itunes writes to.
So "restoring" may take time, but can sort out a lot of problems. I "enable disk use" from within itunes and have used the "hidden ipod commands"
http://www.command-tab.com/2006/03/30/hidden-ipod-commands/ that have solved many problems without upset.
The very best of luck (but do remember to check if you had any viruses in your windows machines; i have had years of great experience with ipod and windows with no hitches)