Once you have read all the books, it doesn't matter in which order you re-read them, I agree. However, if you have never read them (nor seen the movies), I think it is critical to start with LWW so that you encounter Aslan in the same way that the children did, with no idea who he is -- if you read MN first, then you already know who Aslan is, and you don't get the delicious feeling of hearing his name for the first time and wondering why it makes you feel so good, as the children did ... It's a wonderful beginning for all the adventures.