Met David Hayter (voice of Snake, from the Metal Gear Solid games) at Anime Expo '08.
Actually, I've seen him a few times now. Every previous time was an organized event, with strict things you could and couldn't do, so it normally consisted of merely getting something signed and/or a photo. And while there were a lot of events at AX with those same rules, because this was over 4 days, there was a lot more chances for people to get stuff signed, so less stress.
Actually ended up running into him in the hallway after a panel on the last day. He was being mobbed for signatures. I decided to just to say Hi.
When I got up the front, I told him "Oh, I've already had you sign a couple things already, so I'm good. I just wanted to say thanks for being so good to your fans. You stayed two extra hours for us in Hollywood, and all the stuff you've done here has just been over he top amazing. It's really meant a lot to us, thank you."
He said thanked me back and asked if there was anything he could do for me.
:)