GIMP!
Have been a big fan of GIMP for many years, only using Photoslop for final exports or conversions of CMYK images. I have a decent workflow with GIMP in conjunction with Scribus and Inkscape too.
Progress with the switch to GEGL is a fantastic milestone as I believe that will allow easier integration of CMYK handling at some point in the future. It's been a few years since I dropped into the GIMP IRC to ask about CMYK though, they don't like that question very much ;)
Ok, so it's not as polished as commercial software with a budget millions of times larger. But what an amazing piece of software, that anyone can use, for free. FREE! So just let that sink in before you diss it.
Biting the hand that feeds IT
