I've switched to using foobar2000 (http://www.foobar2000.org/) and I think it's the first music player that I actually like. It's extremely simple and I've found it quite fast and responsive, even on my netbook.
I'd also strongly recommend foobar2000. It's incredibly fast, automatically adds music pretty much as soon as it's in the directory, is extremely customizable, and can look really, really nice. It has customizable global hotkeys, addon support, but works well out of the box.
If any one is still trying to use iTunes on Windows, I strongly urge you to at least try foobar2000. Once I switched, there was just no way I was going back to iTunes. It alleviates so many of the stupid daily annoyances I had with iTunes.
