Install Ubuntu Restricted Extras

sudo apt-get install ubuntu-restricted-extras

Ubuntu restricted extras is a single package contains lot of use full plugins and extras that essential for ubuntu. It is not installed by default due to the license restrictions of various softwares. Restricted Extras contains softwares given below.

flashplugin-installer
gstreamer0.10-ffmpeg
gstreamer0.10-fluendo-mp3n
gstreamer0.10-pitfdll
gstreamer0.10-plugins-bad
gstreamer0.10-plugins-ugly
gstreamer0.10-plugins-bad-multiverse
gstreamer0.10-plugins-ugly-multiverse
icedtea6-plugin
libavcodec-extra-52
libmp4v2-0
ttf-mscorefonts-installer
unrar

http://packages.ubuntu.com/quantal/ubuntu-restricted-extras