I just tried Krita and wow.

I don't think I'll ever use paint.net or gimp again. I can't recommend this enough, it blows my mind that such quality freeware exists. I've only been trying it for an hour, but already I've found a hundred things I couldn't do before. Not much of a photoshop user, but I truly believe Krita to be of the same quality level (maybe even higher, for the low price of free).

Hope this resource helps someone else!