Oh man, can I ever answer that question after hours of research and many program trials! There are quite a few out there–you’ll hear “Floola” “Songbird” “Media Monkey” “WinAMP” among the better-known ones–and it really depends on what you are looking for. I settled on Media Monkey because the others I tried (a good many of them) lacked multi-folder capabilities: aka, all your music is jumbled into one huge playlist. I wanted major organizational power. The only thing I don’t care for is (and to my knowledge, no other program other than iTunes has this capability) that it won’t sync sub-folders to the iPod. So I can’t have a master “Broadway” folder and have sub-folders for “CATS”, “Phantom”, etc. But, in program size, functionality (pretty bug-less), design, and most importantly, organization control, Media Monkey is the one for me.
If you want to do more research, type in “Best ITune Alternative” in Google and get a general idea of programs. Before actually downloading one, because they are typically pretty bloated in size, do another search for “[potential program] review” and a lot will come up that way too.