Art Still and Dan Saleamua are a couple of my favorites. Not only are they incredibly nice, but they're a hoot as well.
Jan Stenrud was by far the most gracious of all the athletes I've met. He stopped talking to a couple of his former teammates and took and introduction from Walter White, then listened intently to everything I had to say about 37 Forever. I felt like he was sincere and genuinely cared what I was saying. A lot of athletes appear as though they're going through the motions and can't wait until you'll shutup and go away. Willie Lanier - the most uncool of them all. I jerk his chain every chance I get now. At the 101 banquet in March, I kept calling him Bobbie Bell.
He did not find it nearly as humorous as I did.
Kimble Anders is near the top, too.