Ok...with trepidation, I'll attempt a Robert Gentel, because the PF folk may be very curious.
Of course, all this stuff is highly subjective. Also, I seem to be the only one getting all soppy, which is kind of embarrassing...I suppose I am just soppy.
Some of us have cyber-"known" RG for a decade or more.
I am trepidatious because he can cut your head off with a smile, he can take a happy day and suddenly make it seem all vile (I gather I am good at this, too.)
You'll see all kinds of reactions to RG as you explore the site. Thing is, he has the steel guts to raise his head above the parapet constantly, and DO things. As we all know, as soon as you raise your head above the parapet a bunch of people will hate you and shoot at you just because you are there.
Rob is a mercurial oxymoron wrapped in a pratfall.
I have met many folk on the net over the years whom I treasure, and he is amongst the treasures.
He is frighteningly intelligent and omni-curious and omni-informed; a kind of Renaissance Elf.
He has a passionate commitment to spreading knowledge, macro social justice, using the net as an instrument of enlightenment and being a witty galoot.
He has a glorious sense of humour, utter integrity about what he does, utter commitment to what he does and utterly ridiculous and unrealistically high standards, which can lead him to being a wee tad difficult at times.
He's a relentless debater...which means some of us want to throttle him while enjoying what we learn at the same time, while others just enjoy. (I am a throttler.)
I think he is one of the unusual humans who is genuinely more wedded to compassion and social action at the macro rather than at the micro level.