TrueBrilliance2!!!
It has the best image quality I've ever seen on any native Amiga chipset program.
I've never seen a program eliminating HAM8 fringing effects like Brilliance2. I think it uses the Copper in conjunction with HAM8 so the result is better than just HAM8, you won't distinguish it from a true 24bit picture. Infact most likely, most of the pixels are in true color for most pictures.
DPaint, I kinda got using it for some stuff but it doesn't support 24bit images. Same for PPaint despite the fact that it can use Gfx cards.