Next in the series after Tommy Burns In three categories Best win: In terms of quality of opponent, and manner of victory Most important win: In terms of historical significance Most spectacular performance: Not really the quality of the win, just a great display of the champion's ability. My picks Best win: Sam McVea 1904 April 22nd, McVea had a 1st round KO over Denver Ed Martin, and I think peaked sooner than the rest of the black triumvirate. In this fight Johnson won easilly, barely being hit until he KOed McVea in the 20ths Most important win: It has to be the fight of the century, James J Jeffries This content is protected Most spectacular performance: I'm going to go for his domination of underrated Champion Tommy Burns This content is protected
Best win? Burns. My reason is both Mcvey ( 18-19 ) and Langford ( 20 ) were far too young when they lost to Johnson, and Jeannette a raw novice with a losing record at times. Burns at least was the champion of the world. Most important win? Burns again. Without this win, he might never be champion or face Jeffries. The irony is he would have liked faced prime versions of Langford, McVey, and Jeannette which would have shown boxing who the best of the four was when they were all in their primes. Most spectacular performance, on film its Burns. By result, I'll go with his KO in 2 rounds over Denver Ed Martin in 1904.
McVea was young, but he seems to have been someone who matured and peaked at a young age. How well known even is his early life, has his age actually been confirmed?
This is an interesting one, because it is not straightforward in any category. Johnson's resume is something over a quantity over quality one, so you could make a case for about half a dozen fights as his best win. I would entertain arguments for Martin, McVea, Ferguson, Burns, and Jeffries if you think that he had something left. For most important you could make a case for the Burns win, or the Jeffries win. I think that I broadly agree with the picks in the OP, for the reasons given.