Isaac Asimov: "The only people I ever met whose intellects surpassed my own were Carl Sagan and Marvin Minsky."
Pretty egotistical to frame it that way of Asimov.
There are a bunch of adjectives I would use to describe Asimov, and egotistical is so far down the list I'd get bored listing them before I got to it. It seems likely to be a realistic and honest self-assessment, on the basis of the breadth, depth, and foresight, of Asimov's written work. If you're Usain Bolt, is it egotistical to say, "I'm probably the fastest runner in the world?" Why is intellect so much different? Sure, there's no precise measure of intelligence...but, someone with great intellectual achievement gets to, at the very least, lay claim to great intellect.
It would be easily dismissed if said by someone much less accomplished. In this case, I just take it as a frank statement of belief.
Regardless, I think it's safe to say Minsky was a great intellect, of a caliber not often seen.