Mplayer is one of most known movie players in Linux, and also in Mac OS, and Windows. To install it in Debian / Ubuntu run:
sudo aptitude install mplayer
Mplayer has lots of options, and we will explore some of them here, the files format it can play according to its official site are:
MPEG/VOB, AVI, Ogg/OGM, VIVO, ASF/WMA/WMV, QT/MOV/MP4, RealMedia, Matroska, NUT, NuppelVideo, FLI, YUV4MPEG, FILM, RoQ, PVA files, supported by many native, XAnim, and Win32 DLL codecs. You can watch VideoCD, SVCD, DVD, 3ivx, DivX 3/4/5 and even WMV movies..
Playing your music/video files
If you want to play your local files just use this command line: