I met the guy along with Peter Lawford on the set of a long forgotten film called 'A Man Called Adam.' My aunt was production secretary on the film, and had arranged for the producers to rent some of my toys (I was 10, maybe 11) to be used as props in the film. She also managed to get me on set for a little while where I met the cast.
Sammy Davis, who I was already taller than was as warm, kind, and as gracious as any performer I have ever met. He was patient and took the time to really simply chat for a while, even though I was breaking up a serious looking poker game.
As an aside, as much as I loved Peter Lawford the actor, I was far more in awe that I was meeting someone who had been married to a Kennedy.