If you like DPaintIV so much (and who doesn't), check out Brilliance 2.0 as its worthy successor.
I saw Jim Sachs at an Amiga User Group meeting in Riverside, CA before the Commodore bankruptcy demonstrating it just before the official release and in his hands it was truly something amazing! In my hands, not so much amazing, but still a great piece of work.
Also, if you can get your hands on a DCTV and/or OpalVision card, the paint programs that came with those two hardware devices were top notch as well.