There's something called Open Canvas that I used as a step between MS paint (yes, that oldschool, haha) and photoshop. It's pretty good from what I remember, though the latest versions cost money, there is still a free version available here: [link]
GIMP is one of the only really good free drawing programs that can be downloaded. May I ask what your issue with it is? Have you considered PaintTool SAI? It's only $60, which is extremely cheap for all the amazing stuff it does.