Audacious
Music Player Listen to music

Audacity
Sound Editor Record and edit audio files

Avidemux
GTK+ Video Editor Edit your Videos

Boxee
Boxee is the best way to enjoy entertainment from the Internet and computer on your TV

Cinelerra
Video Editor

Clementine
Clementine Music Player Plays music and last.fm streams

DeaDBeeF
Audio Player Play music

EasyTAG
Audio File Tag Viewer/Editor EasyTAG is an utility for viewing and editing tags for MP3, MP2, FLAC, Ogg Vorbis, MusePack and Monkey's Audio files, with a GTK+ GUI.

Exaile
Music Player Listen to, explore, or manage your audio collection

HandBrake
DVD Ripper Transcodes DVD and other media

ISO
ISO File Editor Read, write and modify ISO images

Jahshaka
video editor video editor

Jokosher
Jokosher audio editor Simply and easily create multi-track audio

Kazam
Screencaster Record a video of activity on your screen

MPlayer
Multimedia player Play movies and songs

Minitunes
Music Player Play your music collection

Qtractor
Multi-track Sequencer Qtractor is an Audio/MIDI multi-track sequencer application

SMPlayer
Media Player A great MPlayer front-end

ScreenTube
Screencast Recording Application Record and upload a screencast

Spotify

VLC
Read, capture, broadcast your multimedia streams

XBMC
Media Center Manage and view your media

Xnoise
Media Player Organize and play your music and video collections

ffmpeg

gPodder
Media Aggregator Download audio and video content from podcasts

Minitube

guvcview
GTK UVC video viewer A video viewer and capturer for the linux uvc driver

Mixxx
Digital DJ interface A digital DJ interface