Ooh, Katherine Mcnamara! I'm a bit envious because, well she's very easy on the eyes.
A few of the celebrities I've (sort of) met have been at conventions, too. I met Mickey Dolenz of The Monkees at a car show and got an autograph for my sister, which she promptly lost! I wish I'd kept it.
I had Peter Mayhew bump right past me at a convention and started to object but then I saw who it was and said to my wife, "Hey, it's Chewie!" At the same con, I saw Ray Park (Darth Maul of Star Wars: The Phantom Menace fame) on a small stage where he was supposed to demonstrate his martial arts skills he performed as Darth Maul, but he'd hurt his ankle not long before, so he was limited in what he could do. Still, he got a kid up onstage with him
and the kid had a light saber, as did Park. Hurt or not, he still displayed some cool moves but he let the kid win, of course. Cool dude.
At one convention, I saw Richard Hatch and Dirk Benedict together in a small side room with a small amount of fans (about 30 or so) and we were seated about 10 feet away from them. They were trying to get a revival of Battlestar Galactica going and were talking about it but I don't remember what it was exactly about, just that it was supposed to be a continuation of the old show. Then a few years later, suddenly the Ronald D. Moore series of Galactica came on so I knew the revival had fallen by the wayside. Still, it was neat to see Hatch get a role on the show.
At a convention, I "sort of" met George Takei. My wife and I got a bite to eat first as it took place at a hotel. At the same restaurant, the only other people there were two convention workers (with their badges on, that's how I knew) and they were sitting with George Takei, who was laughing in that deep voice of his. Later, we just happened to be walking by a door after Takei's appearance and they were ushering him through that door and he looked at me and said, "Howdy!" That was in my home state of Texas and although he was friendly, I groaned inside because I thought he assumed everyone it Texas said that when greeted. I've never said it in my life except to relate this story.
My personal favorite is being about two feet away from Helen Slater of Supergirl (the movie) fame at D/FW Airport. I was there picking up my fiancee, who had just come back from a trip to Italy (her family had lots of money). She and her mother were busy sorting luggage when I looked to my side and there was Helen. Since I read science fiction magazines back then, I knew what Helen looked like and that she was at the time making The Legend of Billy Jean in Texas. Well, there she was with her hair cut short but still beautiful. I swear our eyes locked and there was some nice tension for a few seconds. I smiled. She smiled. I remembered I was with my fiancee and had to turn away. She did too as she was with a couple of suits (one woman and one man) and so we parted, never to meet again. *sigh*