2D art: GIMP, Painter X; Both have good capabilities, but Painter has enormous kickstart when you are finishing/polishing 2D art such as decorated concepts
3D art: Blender or MAX
Animation: Blender or Maya; In Maya PLE at least the workflow was pretty smooth
Model Design: Blender; Teh ultimate.
Audio editing/creating: -- You have to be at least level 16 to be able to edit audio streams.
Video editing/creating: -- You have to be at least level 19 to be able to edit videos.