What do you mean, what's wrong with itunes?? i use that to listen to music in my computer (mac) and i've never had a problem with it.
I just personally find it to be a cumbersome, inefficient thing. I'm very anal about the arrangement of my library and I constantly add and arrange music on the comp. From the looks of things, I need to reinstall iTunes or something in order to relocate everything and get rid of all the damn !. It doesn't look to be worth it to me. WMP (Windows Media Player) will usually find the new path without the bullshit. If I need iTunes to add things from my library, it'll sluggishly trod on through where WMP finds the files and is done with it. iTunes playlists pop up in other windows, which annoys the fuck out of me. iTunes' album view takes up way too much visual space. I have WMP with an album view and it's nice and compact. For whatever reason, files that manage to stay together in WMP separate in iTunes. Need album art? I don't have to do any wonky "get album artwork" bs. Album art for "Bleed" by Razorblade Monalisa can't be found? No shit; they're not on iTunes. Meanwhile, for WMP I just go in and paste it myself. I can change the color on WMP. I can have pictures fly around in full screen as my music plays. That "authorize/deauthorize" stuff is total crap. I wouldn't even bother with iTunes-anything if they didn't have stuff I couldn't find anywhere else.
The only other thing that I notice iTunes lovers grab upon is that the sound quality is better, but let's be honest: I don't have any high-end equipment. And due to the small sizes of my pc and mp3 player, even when I get high quality tracks, I have to rip them to a smaller bit rate and sacrifice said-quality anyway. So I have no way of verifying that claim myself.
Granted, it may work great for your needs. I know it does for Merla's. She loves her some iTunes. But it fails colossally for me.