The best mp3 player for this situation?

Here's the rundown of what I'd like:

1.) It should have at least 100 GB.
2.) I'd like it to be easily compatible. I've got an entire collection in Itunes, and I'd like to start using windows media player to store my collection on the computer. Point being, I'd like it to be flexible with all the file types that all of that requires. (or if you can just tell me how to convert the itunes collection into whatever file type the model you reccommend needs for free, that's fine too)
3.) I want it to work like a jump drive, with no necessary software. I just want to drag and drop the files onto it from any (or most any)computer.

(the rest of my points here aren't absolutely necessary, just overall preferences)

4.) The only, and by only I mean the only, single, one extra feature/add-on/etc that I'd like for it to have besides playing my music, is photo playback. Even then, I'm willing to go without it if there's anything that fits the above three points without photo playback.
5.) Good audio sound would be preferable, but I'm not even sure if that depends on the model or brand, rather than the headphones or files.
6.) A good user interface that lets me navigate easily through a very large music collection would be very helpful, but not necessary.
7.) A good battery life would be nice, but I'm willing to sacrifice it for the price's sake.
8.) Of course, I'd like something that has a good track record of not breaking down or messing up from maunfacturing errors of any kind.

Nothing besides any of these points matters to me. I'd really like for it to be under $200, and that can mean getting it used online. So considering all of this, what would be my best bet and why?

And thanks so much for the much needed advice. I'm just having such a hard time getting the right information myself. I'm not biased to any brand or model...Just whatever happens to fit the bill here best is what I'm dying to hear.

P.S.-My computer is a Windows Vista, in case that's important for any reason.