Blender is an excellent 3D modelling, animation and game-making application: http://www.blender.org/
Renderman is the tool that’s used for rendering movie effects and computer animation, free implementations are available: http://www.renderman.org/RMR/OtherLinks/index.html#Renderers
For video editing there’s Kino: http://kino.schirmacher.de/
For frame editing there’s CinePaint (formerly Film Gimp), developed and used by Hollywood effects houses: http://www.cinepaint.org/
For photo and image editing there’s Gimp: http://www.gimp.org/
For vector illustration there’s Inkscape: http://www.inkscape.org.
And there will eventually be minara 🙂 : http://minara.sourceforge.net/
For fonts (typefaces) there’s Fontforge: http://fontforge.sourceforge.net/
For desktop publishing there’s Scribus: http://www.scribus.net/
Other Free Software media resources, including sound, sampling and sequencing (which are outside my area of expertise): http://lib.fo.am/cgi-bin/view/Libarynth/FreeMediaTools