What is your ideal cast ( in your mind without thinking of the show)

There is no obligation to choose someone who have the exact age of the characters now just who could fit as the character for you and it could be someone really old now but in his or her youth would have fit (don't know if it really English sorry!)
I know the show is great, the actors are good but I want just to know what you think just with your imagination and the books.
Thanks!!!