Dude, that is seriously awesome. The way you were able to get not just a reply back from the very stars you illustrated, but also getting a picture of them HOLDING your drawings and posing with 'em. Totally cool, you really must have had a blast doing these and getting the reactions you did.
The closest I've ever gotten to something similar is when I drew American Idol Season 6 third-place contestant Melinda Doolittle a portrait of herself and sent it to her shortly after one of her best performances on the show. She never replied back, but many years later I followed her on Twitter and sent her a tweet with the picture attached to it, and she replied back saying it was really cool and said thank you after that. She even replied again to one of my replies to one of her other tweets about one of the contestants from last season, haha.