I am still using WMP (I know dont flame me!) for mp3 files.
I only use it because I like the "Ocean Mist" theme.
For all my video and other audio formats (cept for real player I dont use those files at all) I use Zoom player.
I like it for the main reason that you can customize what seems like 3 pages of hotkeys. And you can fast forward/rewind/skip, pause, take screenshots etc all with the keyboard.
Its really irritating how WMP only allows you to use the keyboard for navigation on only SOME files.