Best - Steve Garvey. Sat directly behind him at a Dodgers game about 20 years ago. Understand that I was 7 in 1979 when I attended my first Dodgers game, so Steve Garvey was a real big deal to me. Through the first 5 innings, Mr. Garvey must have signed 100 autographs from fans approaching him. Even though I was seated directly behind him, I was iffy about asking for an auto just because he was there with his family and dealing with so many people asking for auto's. I eventually ran to the souvenir stand and got one of those cheapo team logo balls and waited until the inning finished. Mr. Garvey was extremely nice and we were able to talk for a short bit. Still have the ball displayed:
In person I always address the signer as Mr..... Even though I'm mid 40's and some of the signers are younger than me, I've found being polite and a bit formal goes a long way. My other really positive experiences were Pee Wee Reese, Ernie Banks, Orel Herschiser
Shawn Green, who was extremely nice and has a very distinctive and elaborate signature:
And even 90 year old Tommy Lasorda who was a surprise replacement for Scott Alexander at Fanfest this past Saturday. A boisterous "Good afternoon Mr. Lasorda!" worked wonders. FWIW, his time was supposed to be 2:50pm to 3:40pm, but he stayed until 4:30 until he had signed for everyone in line:
Worst ever was Dave Winfield. I was still a kid...around 22 when I got his autograph at a show. Wouldn't look up or acknowledge me at all. Signed off center badly on the ball...just not a pleasant person.