Okay, it’s not the audio (media) player but the dependency. But hey, foobar2000 can be installed on a fresh Windows XP (and above) install without any extra addition with 2MB installer. Or if you prefer Winamp, it only weighs 10MB.
And the dependency (freepats), um, why does an audio (media) player need synthesizer?
Note that I won’t use the video player functionality since I doubt it supports .ass (or does it? AFAIK the only media player that kinda-properly support it is mplayer and its frontends)