Foobar2000 Media Player is a very very recommendable player. It is developed by Peter Pawlowski who used to work on Winamp3. FB2000 uses a plain and simple UI - no skins, no fuss. Current version is 0.55 beta which does not require an installation. Filesize is as small as 245kb, while in playback mode the player approximately consumes 1.9Mbyte of your RAM which is so much less compared to Winamp or MS Media Player. Various optional plugins are available too.
Foobar2000 homepage - download here Changelog: workedaround problems with certain shortcut keys seeking keys are now customizable added "write id3v1 only" for mp3 mpc tag updater kills id3v2 tags now vorbis tag updater kills id3v2 tags now mp3 tag updater optionally kills id3v2 tags now more intelligent responses to doubleclicking status bar "restrict filenames when adding directory" option