Holden, def Holden, he's a timeless character that has represented the feelings and emotions of oh so many people. Plus J.D. Salinger writes the most intriguing characters so, Franny and Zoey would be up on my list too.
This is tough. Maybe Kunta Kinte from "Roots". He was very brave. Jane Eyre, Ebeneizer Scrooge, the poor workhorse from "Animal Farm", Lady Macbeth, and Anne of Green Gables would also be interesting to meet, and the vampires from Anne Rice's books, though you'd probably end up sucked dry. Kunte I think though, would be the most interesting. (Macbeth counts because when I read it it was in book form)
personally I'd hate to have Holden come to life, I swear, I have to deal with enough cynial young men to want to meet another one, even though he is way more eliquint than most of the "men" I have to deal with. I'd love to meet Kris Bjornson from McCaffrey's Freedom series or Sydney Carton form Tale of Two Cities, Yes I do know that he too is a cynial man, but he is cynial about different things than Holden.