I would LOVE to meet Gandalf. xD He's badass! And to stay at Lord of the Rings, meeting an Ent might make my whole life a bit more... calm... ^^
Plus I'd love to meet some charakters from one of my childs books, esp. Juniper, who is some sort of witch, but totally into nature and harmonic to the point of being annoying, so having a lemonade with her would be veeery interesting.