Thanks everyone for your opinion. I think that I will read them by publication order. I will be starting the series tomarrow when I take a trip to colorado!!
They're interesting books. I loved them as a child; when I reread them as an adult, their didacticism really turned me off. I wish I were better now at ignoring the Message in Message books; I wish I were still able to enjoy the Narnia chronicles.
Except for Horse & His Boy, which I was never able to finish. Magician's Nephew was always my favorite, followed closely by Prince Caspian; I like the darkness.
Horse and his Boy never felt like it was quite part of the series.
If I were doing the movies, I'd do Lion, Caspian, Treader, Chair, and Battle. Then if there was still a market for more Narnia among the fans, I'd do Nephew. And only come back to do Horse if there was real demand.