I have met a few famous people.
If you look on my profile, you'll see that I met Eliza Dushku a few years back. I was pretty starstruck since I had the biggest crush on her since Bring it on. I almost fainted when she said she liked my Minecraft shirt.
Other famous people I've met at conventions: Christopher Lloyd, Wil Wheaton, and Julie Benz.
I also met Peter Dante at Disneyland. I dunno if he can really be considered "famous", but he's in a bunch of Adam Sandler movies.