There was a time in recent history when Winamp was the one and only fully skinnable, full-featured media player. Now that Winamp was bought out by AOL, more and more additional features are only available at an additional charge. AIMP is the alternative to Winamp, with great a large community that provides skinning options and plugins. Additional features such as CD-ripping and sound recording are included for free. If you've only known Winamp, give AIMP a try. It has similar looks at features that you'd be used to.
Please note that AIMP DevTeam's website is in Russian, but there is translation on the right side for English.