VLC (initially VideoLAN Client) is a highly portable multimedia player for various audio and video formats, including MPEG-1, MPEG-2, MPEG-4, DivX, MP3, and OGG, as well as for DVDs, VCDs, and various streaming protocols.
It also can be used as a server for unicast or multicast streams in IPv4 or IPv6 on a high-bandwidth network.
VLC Media Player - Download
Probably most of you allready have it or know it ...
But still for the ppl who dont know it yet it's a nice media player.