NEW version Vs. BBC version (an actor by actor comparison)
First of all, let me stress that the BBC version was made in 1988, so I'm not going to compare its quaint effects to the estimated $180+ million budget of the new version. I'm going to compare the individual acting/performances and say which one I thought was better.
PETER: BBC. The actor was better and had a more authoritative and regal presence, something the oldest brother should defintely have.
EDMUND: New. He was an excellent actor because he did so much with his eyes and he was very believable as being a selfish, troubled young boy.
SUSAN: New. While I don't think she was an excellent actress, she at least gave the character some depth, something the BBC actress lacked.
LUCY: New. What can I say, she was good and she was adorable, though sometimes she looked happy when she was supposed to be sad. The BBC actress was a little annoying, though she did portray the naive side of her character very well.
WHITE WITCH/JADIS: BBC. This actress had a GIANT (maybe a little too giant?) and evil presence, she was more regal, and she was genuinely frightening when she needed to be, something that was lacking with the new actress.
MR. TUMNUS: BBC. He played the nervous and anxious side of his character brilliantly. I don't know how else to put it, but the new actor's performance was too 'modern.' His expressions and mannerisms seemed too familiar and modern, if that makes any sense.
ASLAN (voice): BBC. When he spoke, he had a calming yet authoritative tone, and his words sounded like they came from his depths, exactly how I imagine a lion would speak. As much as I like Liam Neeson, he sounded almost too gentle and kind.
MAUGRIM (voice): BBC. Yes, the wolf costume was corny, but his voice was scarier and much more wild and threatening than the New version.
MR. BEAVER (voice): New. He played Mr. Beaver's quirky side very well, while the BBC actor's portrayal was perhaps a little too whiny.
MRS. BEAVER (voice): BBC. She was funnier and more motherly than the New actress.
LITTLE MAN(bbc)/GINARRBRIK(new): BBC. In the credits, the two versions each gave the White Witch's right-hand dwarf a different name. The BBC actor had more authority and presence, while the New actor's character was more unpredictable (and therefore could be seen as slightly more threatening), he ultimately was more comical than he was scary.
THE PROFESSOR: BBC. The actor absolutely brilliantly played the character as a studious yet quirky old man. And even though The Professor has very little screen time, he gave his character depth, which I thought was lacking in the new version, who seemed to play his character as more of a confused/kooky old man.
MRS. MACREADY: New. Although the BBC actress perhaps played the character more realistically, the New actress made her more frightening, which is exactly how children would probably see her.
If you're keeping tally, that is 8-5 in favor of the BBC version. Now, you'll have to decide for yourself how important and crucial each specific character is to the story, but if you're comparing overall performaces, I think the BBC version is better (again, excluding visual effects).
Half a truth is often a great lie. -Benjamin Franklin