Here's mine:
I got this ball signed by Sandy Koufax at Dodgertown in Arizona during spring training 2015. My dad and I have been going to spring training together for a really long time now and every year we went to Dodgertown in Vero to haunt Sandy Koufax. We'd always heard he was known to show up unannounced every now and then and blend in while he was there but we never caught sight of him. But in 2015 after the Dodgers moved to Arizona the Dodgers I guess paid Koufax to come to spring training. The first day we were there we snagged him. And this was before he started doing his line up. I'll never forget the look on my dad's face.
I have other Koufax balls but I'll always have this one.