I once worked backstage on a Philip Glass opera ("Les Enfants Terrible" during Spoleto Festival 1996) and literally ran into Glass backstage. The man is a TREE.
I met Mike, Kevin, and the Mads (twice) at the MST3K Conventioconexpofestaramas. Frank liked my t-shirt, and I was able to get a photo with them.
Chuck Wendig allowed me to stroke his beard at Tucson Book Festival (it was a dare from my publisher. CHALLENGE ACCEPTED). I also met author Cornelia Funke, who was extremely nice. And she may not be AS famous, but I'm friends with author Sue London -- also my publisher for most editing gigs -- also the one who dared me to pet the wild Wendigo.