SMPlayer is a free open source multimedia player, often use to play audio and video files (such as mp3, ogg, flac, avi, ogm, mkv). It is actually a frontend for MPlayer, providing a convenient graphical interface to control the player. This provides the power of MPlayer combined with the ease of use players like Totem.
smplayer can be installed in the Software Center or with APT. It is comparable to VLC (an alternative to MPlayer of comparable capabilities), though SMPlayer's interface does not provide access to all the features of MPlayer.