I don't need Paint Shop Pro because I use Photoshop, but I like to stay familiar
with it. I picked up the latest version for $49, an amazing piece of software for
that price (regular price is $99, Photoshop is $650).
Version 5 of Swift 3D, used to make 3D flash objects and/or movies. A good
program to learn 3D in general.
Version 4 of Toon Boom Studio, for creating cartoons.
Artrage, version 2. Fun to play with, for sure.
Manga Studio, for manga and comic illustration
Anime Studio, version 5, for all stages of cartoon development.
Software
Keeping up with new versions of software -- just because it's fun to learn.
Here I am playing with a painting of mom in Painter X.