Download Windows Essential Codec Pack
This superb software not only comes with a great, light-weight open source Media Player, it also comes with an extensive set of codecs that will allow you to play 99% of the video files out there in the web or in your computer. Although it may look like a regular old fashioned video player, it comes with some nice extras, for example, a built in DVD player with real-time zoom, support for AVI subtitles, QuickTime and RealVideo support, and much more incredible surprises.
This media player is absolutely clean, it has no adware, spyware or viruses. It's easy to install or uninstall, but even more easier to use. Being published under the GNU GPL open source license makes this great software 100% free. Definitely a great alternative for the huge and sometimes clumsy media players out there.