I recently finished The Silver Chair, read by Jeremy Northam, which by the way, was my least favorite book in the series (the foreshadowing is way too obvious in this one) and The Last Battle, read by Patrick Stewart (think Star Trek).
Taken as a whole, The Chronicles of Narnia is an epic adventure, a children's classic, and a thinly-veiled nod to the Christian faith. Some of the individual books stand well on their own, particularly The Horse and His Boy (my personal favorite, read superbly by Alex Jennings), and to a lesser degree, Prince Caspian, The Lion, the Witch and the Wardrobe, and The Voyage of the Dawn Treader.
It was sometimes distracting, sometimes disappointing, and sometimes refreshing to hear each book read by a different actor. Alex Jennings and Michael York (of Austin Powers fame!) were my favorite narrators, each providing rich characterizations for the story's many characters.
All the books should be easily available from your public library in either CD or digital download