Jane Goodall - fucking amazing. She was my idol growing up, and I was practically speechless being in her presence.
Pele - Lovely man.
David Beckham - Also very nice. Very kind to his fans.
Sheikh Mohammed Bin Zayed Al Nahyan, Crown Prince of Abu Dhabi - Incredibly humble and very polite.
President Moon Jae-In - Can't say I really spoke to him much, but he seemed nice.
Dick Clark - former head of US Homeland Security. Nice guy. Type of person you'd love to have a beer with.
Steve Wozniak. Nice guy, but was very rushed meeting.
I also met the Director General of NASA, James Frederick Bridenstine, although I don't think he classifies as a famous person. He was very impressed (or at least acted impressed) that my son could name all of the planets and dwarf planets at 4 and said he couldn't wait to work with him someday. So he's probably my second favorite "famous" person I've met after Jane Goodall.
A few other Nobel prize winners, heads of internal agencies, etc. But none that are household names.