There are of course many brilliant programmers who are not into open source (like Philip Zimmermann), I don't deny it.
A few people off the top of my head who are noted for being good programmers but whose code is I think mostly not publicly available: Peter Norvig (though I doubt he's writing much code nowadays), Paul Graham, Sophie Wilson, Charles Simonyi (though it'll be a while before he's forgiven for "Hungarian notation").
(I should add in the interests of fairness that while I was typing that list my brain was angrily trying to remind me of Jamie Zawinski and Don Knuth, both of whom are much more open-source types.)
Yes, that was my point, I don't say there are no good closed source programmers, just it's much easier to be known/respected as a good programmer by writing free software.
Anyway, John Carmack.
Commander Keen, Wolfenstein, Doom and Quake were all absolutely ground-breaking. Probably ditto for the megatexture stuff in Rage.
It's fun to hate on Zuckerberg, because it's Facebook. But the guy produced brilliant stuff that was ahead of it's time.