I've only met one really famous author, and that was Raymond E. Feist when he came to do a signing in Wellington. I have a signed copy of the extended version of Magician. This was years ago now. I remember we had to wait in line for ages and that he was not doing dedications, just signing his name. He was complaining bitterly to his assistant about the quality of the coffee while he signed. Wellington has a great café culture and so I remember being offended about that. I know, now, that most big-name authors won't do dedications at bookstore signings either, because there's just not enough time. But at the time I was really disappointed.
One author I would love to meet is George R. R. Martin, author of the series A Song of Ice and Fire. He came out to Australia in 2010 for WorldCon. I really, really wanted to go but we couldn't afford it. Now of course he's super-famous thanks to the HBO series of Game of Thrones so I've probably missed my chance :(
This post is part of the above Posting Challenge