I can't think of a specific person. I've met a lot of people who have quite some brain power available. Who are way more knowledgeable than me and faster processing things. Most interesting encounters are when I don't specifically attend an lecture of someone who is very smart, but randomly meet them. Like I talk to an old lady and find out she has a lot of wise words to offer.
And intelligence is quite a broad term. Some people are experts in one domain and are crazy at that. Some have broad knowledge and you can just ask them about anything and they have a clever take on it. Some are book-smart, some handy... And I don't really have a good metric to compare them.