TVPaint and PPaint, for different reasons, are also great. TVPaint easily has the best anti-aliasing I've ever seen in a paint program on ANY platform, it smooths images incredibly even on a low-spec Amiga. It can do a lot of things you'd even require an image processing program like Photogenics to otherwise do.
You can get TVPaint for free from our site, the only requirement is that you have a graphics card in your amiga (doesn't run on AGA or the ECS, older chipsets).
Cloanto's PPaint is great for its powerful dithering algorithms and arexx support, among other things.
DPaint V still has some unmatched features but it doesn't support graphics cards, so usually you'd have to choose between it and TVPaint on the same amiga anyway.
Neither DPaint no PPaint are freeware, though - you can probably find them on eBay, AmiBench or elsewhere, they're still around.
http://www.amigau.com/c-graphics/tvpaint.htmhave fun!
kevin orme
amiga university
www.amigau.com