Winamp for audio, WMP, BS & Cyberlink PowerDVD for video.  Quicktime and Real Alternative when necessary *sigh*
I do kind of like 
this guy's audio player for it's simplicity though!  I'm tempted to try it, but I also sometimes require FLAC.  His does however support mp3, ogg, wav, wma and midi, and is clean freeware.
Did anyone else use Xenorate?  I liked it's performance and features as an "all in one" media player, but they seemed not to ever update it.