VideoLAN is a software project, which produces free software for video, released under the GNU General Public License. VLC media player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, mp3, ogg, …) as well as DVDs, VCDs, and various streaming protocols. It can also be used as a server to stream in unicast or multicast in IPv4 or IPv6 on a high-bandwidth network. It doesn’t need any external codec or program to work.

Free software - AVS DVD player

Play movie DVDs, video & audio files right on your computer with FREE AVS DVD Player. No spyware or adware. Safe to install!!!

AVS DVD Player  is a compact and easy-to-use program that has a simple user-friendly interface allowing you to start watching DVD movies with no additional software.

One more pleasant thing about it - it is absolutely FREE SOFTWARE! http://www.avsmedia.com/DVDPlayer/index.aspx