VLC: Official site - Free multimedia solutions for all OS!
vooPlayer is a professional video hosting solution with a sophisticated suite of video marketing tools that helps businesses grow with video.
Free media player for Windows with built-in codecs and support for Youtube. Plays all video formats (AVI, MKV, MP4, WMV...) No codecs needed. Official site.
Monetize your videos; free online video player platform (OVP) to manage, transcode and host your videos. Free support for HTML5 and Flash video advertising.
FrostWire is a free and easy BitTorrent Client, Cloud Downloader and Media Player for Windows, Mac, Linux and Android Search, Download, Play and Share Files.
Most popular video player with autodownloading subtitles feature in all languages and support torrents streaming.