Boas... 
Julgo que assim é difícil, mas vou colocar aqui alguns que são ou podem ser utilizados em Multimédia, Animação 2D e 3D, Aplicações Informáticas,... basicamente são aqueles que podemos designar de obrigatórios:

Edição de Imagem (Bitmap e Vectorial): Paint.Net, Gimp, Inkscape 

3D: Blender, Google Sketchup

Animação: FrameByFrame, Tupi, Synfig Studio

Vídeo: kdenlive, Cinelerra, PiTiVi

Som: Audacity (chega perfeitamente....)

Conversão de Formatos: Freemake

Não sei se ajudei...

Aqui vão mais alguns programas...

Internet

Instant Messaging

- Pidgin

Internet Browser

- Firefox

- Chrome

- Opera

E-Mail Clients & Feed Aggregators

- Thunderbird - E-Mail,

- Mutt - E-Mail

FTP & SSH Clients

- cURL - FTP

- FileZilla - FTP

- OpenSSH - SSH

- PuTTy - SSH

Multimédia

Audio Players

- Amarok - QT Based

- Decibel - GTK Based

- Music Player Daemon - CLI Based - Music Server

- Audacious - GTK Based

- cmus - CLI Based

Video Players

- VLC - GTK/wxWidgets Based

- MPlayer Extremely powerful movie player

Image Viewers

- GQview - GTK Based

- gThumb - GTK Based

- Gwenview - QT Based

- Mirage - GTK Based

Image Editors

- GIMP - GTK Based

- CinePaint - GTK Based

- Krita - QT Based

Sound Editors

- Audacity - wxWidgets Based

- Ardour - GTK Based

- MusE - QT Based

File Managers

- Konqueror - QT Based

- Nautilus - GTK Based

- Dolphin - QT Based

Misc Utilities

- Osmo - Personal Organizer - GTK Based

- Dia - Diagram Creation - GTK Based

- LibreOffice

- Alltray

- Wine

Personal Video Recorders

Elisa Media Center

Freevo

MythTV

Media Collection Managers

GCStar

Griffith

Tellico

Editors

Avidemux

Celtx

Cinelerra

Kdenlive

Kino

LiVES

Open Movie Editor

Video Samplers

Veejay

Video Streaming

MPEG4IP

FreeJ

Animation

Blender 3D

Stopmotion

Webcam

Cheese  

HasciiCam

Encoding and Conversion

FFmpeg

HandBrake

MEncoder

DVD Authoring & Ripping

DeVeDe

DVDStyler

Thoggen

Tools

dvgrab

recordMyDesktop