I don't use WMP, but my music sounds a lot better when played with iTunes than with the LW player!!

You don't say in which way they sound better. However, you might have a bad default codec for MP3 which is "optimized" for performance rather than quality. I've also read that WiMP uses a filter that cuts off parts of the high frequency range. I would say WiMP is the worst choice for anything (whether video or audio) in any case for many reasons.

thx

that explains a lot. but what is recommended to be used as the best media player?

For Windows VLC is best, for Unix MPlayer is best. These don't offer any library management but that's nothing I need or care about. Of course iTunes does but I think iTunes (and thus Quicktime) is almost as bad as WiMP. For example both can and are abused to popup websites when you try to play the "wrong" files (read: spam). Further both WiMP and iTunes support DRM. This is unacceptable.