fictional by far. Unless of course the book was about me... then I'd want to be who that book was about. Does that make any sense?
As far as specific character just from a book I've read. Definitely Sam Fisher from Tom Clancy/David Michaels Splinter Cell book series. He's cooler than the video game version (even though they are 1 in the same). I'm sure there are others I wouldnt mind being... but as of right now that seems to be who I'd pick.