I think it's funny that so many bad reviews say "I hate it, because it's like a self-help book (written like a parable)"... in reality, many self-help books are based on the same philosophies that Coelho based his book on, but that doesn't make it a self-help book itself. 
 In short, the book's philosophy is strongly based on Stoicism (which is over 2000 years old, so forget modern self-help books), which in my opinion is also compatible with Buddhism (at least some schools). Since Stoicism and Buddhism are my preferred philosophies, I really liked the Alchemist. 
 I found the mash-up with Christianity and Islam a bit ... out of place, but that might be due to my own preferences.