With this free audio editor, you can not only record and play sounds, but also import and export WAV, AIFF, MP3, and OGG files.

Edited by Nullsoft, Winamp is a fast and reliable freeware which can play almost all the audio (mp3, wma, ogg, wav, cda...) and video (avi, wmv, mpg, divx, xvid...) files.

This free software edited by Apple is an absolute must-have, probably one of the best audio players.

If you can't play a video file with a non-common codec on your usual media player, VLC Media Player may solve your problem.