The GIMP
 

The GIMP (Gnu Image Manipulation Program) is one of the best Linux graphics programs.
It isn't quite PhotoShop but not far off it and it's free.

WinGIMP is a Windows port of the GIMP (free under the GPL) that works remarkably well.

first install gtk+:
ftp://ftp.arnes.si/software/gimp-win...0912-setup.zip
ftp://ftp.flamingtext.com/pub/gimp/w...0912-setup.zip

then gimp:
ftp://ftp.arnes.si/software/gimp-win...0907-setup.zip
ftp://ftp.flamingtext.com/pub/gimp/w...0907-setup.zip

then plugins:
ftp://ftp.arnes.si/software/gimp-win/plugin-pack.zip

and gif support:
http://www.iki.fi/tml/gimp/win32/gim...3-20020310.zip

This is not the latest version of 1.2.4 but is much stable then this from:
http://www2.arnes.si/~sopjsimo/gimp/

Pros:
Free. Very able. Lots of filters and effects. Image tubes, textures, multiple layers, masks etc.

Cons:
1) No printing yet. You have to print from Windows Paint (no great problem)
2) Graphics tablet support (Wacom) is buggy but can be tweaked.