iPod doesn't have full compatibility with some windows music formats, I believe, but you can get a player like the Rio Carbon and use a free program called JHymn to put iTunes music files on your player and get to use every music file you run across in your player.
Also, I prefer the font of the Rio Carbon and other windows-based players.
And you get a lot more music space for the price with a windows player.
You miss out on podcasts, perhaps, though. I don't know a lot about those, so maybe not.
I like the silver look and the shape of my Carbon, too.
The only issue I have is that they haven't come out with the software, yet, for the Carbon so you can't use those subscription services to download an unlimited number of songs to your player for a flat monthly fee (like at Napster). But, I think that will be resolved in the next few months, if not sooner.
I've looked at a Rio Carbon ... Overstock.com has refurb models dirt cheap right now, and you can buy an extended warranty on them pretty cheap as well ... but I don't know if you've heard, Rio just went kaput, which means there aren't likely to be any more firmware updates or anything.