Dear Seven:
I would consider exact the opposite: Michelangeli first.
Anyway, let me clarify my point. When I wrote "perfect", the "flawlessness" is just a small percentage of it. I think that a remarkable interpretation go far beyond it, and sometimes even a rendering with a mistake or two is completely acceptable.
Going further, you do agree with me. When you considered Richter, you wrote about his "charisma and musicallity", and that's why Richter is the artist he is. The fact that he have an incredible repertory does not matter. By the way, you seem to "excuse" him for some wrong notes because this amount of pieces. I believe that even if he had one piece in his repertory, he would not play it without wrong notes. However, this is just my speculation.
Now, about Michelangeli, he was a very complete artist, much more than Richter in my opinion, and this is reflected in his somewhat limited repertory. But, something of absolute importance, everything that he plays is perfect.
Well, in the end we're talking about two pianists that I just can't listen enough, and your comparison was very cool, because they were artists of very different styles that are in the highest degree of the pianistic artistry.
Notice that if you think that "more is better", I respect your position. It's up to yourself. Anyway, I am tired of the "hardest"-"biggest"-"whateverest" way. But that is up to me.

Best wishes!