One of the greatest alternatives to Photoshop is Pixeluvo.
It's easier than photoshop and with the most features of it. Let's see if it will improve in the future! (i hope it will improve)
And the best is, that is available for Windows and for Linux (Ubuntu and Fedora).
It is not free but the price is very good (about $32).
Various topics which don't belong to ecology, cooking, farming.