My son and I just finished The Lion, the Witch, and the Wardrobe. What fun! I missed out on Narnia completely as a child, and first read this book with my daughter several years back. Now it's my son's turn to be introduced to the series, and he's all in. I've been told, in no uncertain terms, that we will be starting Prince Caspian IMMEDIATELY. 
 My goal in reading the Narnia books is to read them strictly from a child's perspective, which I'm able to do by reading them aloud with my son. I'm intentionally ignoring the religious overtones and themes -- which interest me not at all -- and I'm focusing on reading these books as pure fantasy adventures. So far, so good. 
 The writing is clever and exciting, the story is fast-paced, and there's humor even in the darkest chapters. There's a reason these books are modern classics! I've so glad to finally have a reason to explore Narnia, and I'm looking forward to the rest of the series.