VLC (VideoLan Client) is an incredible multimedia player capable of playing a great variety of video and audio formats, like DVDs, VCDs, etc.
On top of being free, VLC also has multi-language support, is easy to use and very quick.
Through its plain interface, VLC Media Player has a large variety of functions, with support for subtitles etc.
VLC Media Player allows you to play the best-known formats, which are: XviD, WMV, WMA, WAV, MP3, OGG, MPEG, MPEG-2, MPEG-4, on top of being able to play movies in: VCD, SVCD y DVD.