Dos 6.22/3.11WFWG for me was the best...
I recall 6.x as something of an unexplored country. MS came out with at least 4 different versions of 6, due I believe to patent issues with other companies. Interestingly, advanced features in DR-DOS 6 (remember them?), a year earlier than MS-DOS 5.0, were subsequently 'incorporated' into MS products, and advertised by MS as better than sliced Wonder bread. Really, MS was never much of an innovator. But they had good marketing, and played hardball with everyone. And they hit with corked bats. Those were the days of Microsoft FUD (fear, uncertainty and doubt) in MS advertising and press releases.
Also, as I recall, 6.x retail versions were the first DOS packages where you didn't get a large book explaining commands. You got a smaller, condensed version. Then, after that, you got a four or five page color flyer in the package, mostly an advertisement telling you how great the 'new and improved' features you just bought were. But that's what most folks needed, and wanted.
PS: I had an early first gen Pentium 60 with, I think,
8MB of RAM. That's right. You heard right. 8 MB. Might have been 16, but I think it was 8. With DOS/Windows 3.11 it literally screamed. Even relatively fat programs like Lotus 123. To use 'audiofool' language, it 'blew away' my 486DX2-66. Then, my PCs got progressively slower, as programs and the OS became progressively more bloated. I'm not arguing for a return to the DOS Shell... I'm just sayin' ...