I’m using both GIMP and Krita.

    Although I believe that Krita is more powerful (just gut feeling there 🙂 ), I’m still mainly using GIMP, out of habit, learning a new soft takes much time. 🙂

    But since I’m also a linux user I find it very convenient to use these two, because they are free, and because they are available as linux softs too. 🙂