foobar2000 - great compact player, comes in a number of packages (lite, normal, special). You can read about the features of each at www.foobar2000.org
a few features, masstagger, tag editor, support for just about every audio codec - including lossless FLAC, APE, WAVE PAK, and more. It (with the right plug-ins) can convert files between formats, to wav, supports .cue sheets, and so much more.
It can even playback files compressed into .zip, .rar and .7z (7-zip) archive files - no need to extract them to a folder!