Wow, it was really, really hard to pick between them. They're all such wonderful characters. I ultimately went with Jill, Puddleglum, Shasta and Digory. I wanted to vote for Tirian as well, but only you can only select four, so someone had to go!
Jill Pole is not in a very good place, emotionally, when she first appears in the Chronicles of Narnia, and she really blossoms into an admirable young lady by the time the series draws to a close. I think she's a great role model for girls, and it's really interesting to watch her character grow.
Puddleglum is one of the most unique, funny and inspiring characters in the entire series. From what I've seen, Tom Baker did a great job with the role, but I'm looking forward to seeing another take on it; maybe a little more spirited. I hope they sign a really gifted actor in the role, particularly someone who really understands the character.
Shasta's always been one of my favorite characters in the entire series. He's an underdog from the beginning and you can't help wanting to root for him. He's also very humble and unassuming. I also think he shows some of the greatest courage we've ever seen in a Narnia character when he went back to "fight" the lion. He's a really hard kid to dislike.
Digory's also a character I'm looking forward to "meeting" on the silver screen. His personality is rather unique among the characters in CoN—he's driven and a bit foolhardy and reckless. He has his faults, but they make him interesting, and his virtues are very strong as well: his love for his mother, and his ability to remain steadfast when being tempted by the Witch to give the silver apple to heal the person he cares about the most. That will be quite a scene!
So hopeful that I'll be able to see all of these characters appear on the "big screen" one day!