Adobe Photoshop cs
This is the number one program for the amatuer/pro editing software. There is really nothing else like it.
It was with some excitement that I finally installed my Photoshop CS. I was finally updating from my worn, over-used photoshop 6.0 to the newer, 8.0. Suffice to say I was quite pleased with what I saw. The interface of the program was the same - it looked very similar to 6.0, except, everything was so much more... cleaner. More accessable. New features. You name it.
The program isn't for the toddler graphic artist. It is quite a step up from the provided MS Paint. You would hope so too, with the price!
The features in photoshop are endless - I'm still exploring them. It's these special features like filters, layers and blending options, set photoshop wide apart from other programs. If your crazy about graphics, you'd be crazy not to have it. Coupled with the right knowledge, you can make truly wonderful pieces. There is not enough space to say exactly what photoshop can do... but how about you go give it a go?
You can download a trial version at Adobe's website here.