AmigaOS 3.1 is easily the best of those listed. It has the fewest bugs, the most features and probably is the fastest. It was the best Amiga release ever. I do think AmigaOS 3.9 is the best AmigaOS but there was a degree of eye candy, bloat, and bugs introduced. Some of it was fixed in the later AmigaOS 3.9 boing bags and some can be turned off. The AmigaOS 3.1 release was nearly perfect. It probably benefited from more developers and testing during the heyday of the Amiga.
