On this page I have collected a couple of links to applications that I find interesting and unknown enough to mention.

Anjuta An almost good enough code editor (one coder one code editor).
Audacity Sample/audio editor/recorder.
Avidemux an AVI file editor.
FontForge a font editor
Gschem schematic capture.
GQview image viewer.
Inkscape vector graphics.
K3B cd/dvd writing.
Mplayer a excellent movie player, also supports DVDs.
PCB you guessed that this program is good for?
Scribus DTP.
Sodipodi another vector graphics program