Have you guys tried out
Paint.NET? It is quickly becoming my favorite graphics editor.

Still trying to learn the ropes with it, I ran across several awesome tutorials I thought I would share with you all here:
Scotch Tape - Create a transparent segment of scotch tape
Glossy/Glass Buttons - Create Web 2.0-like glassy buttons
Toy Car - Turn a real car into a toy car
Make a Chain - How to render individual links, then link them together to form a chain
How to make a Lightsaber - Use lighting and blur effects to render a Lightsaber in
Transparent Background - Make the background of an image transparent
Cutting out Images the Easy Way! v2 - Great method for cutting images out of pictures
LiteBrite(TM) Effect - Transform your pictures into coloured peg-board style images
Lets Make a Software Box - Transform flat images into 3D boxes
Drop Shadows - Add depth to your artwork with drop shadows
What do you think?