I've never really read books before. When I do, I can get into them and my favorite series so far is that of Wicked by Gregory Maguire. 

Though they have some similarities, I always think novels are mostly different than RPing and have always had a separate mindset between them. Sure, it can elicit similar emotions and senses, but reading another's work about an entire world and discovering it through their interpretation is much different than conversing about ideas with a group of people and constantly developing it as the RP goes on. There's an omniscience with RPing and an expectation that you don't get from reading a book. Characters aren't created by you, you don't know their background going into it. It's exciting, to that degree, to read a book.

However, I've yet to read a book or series since then and have always been in my own mind about creating my own world and story. I believe I'm getting into wanting to write a novel rather than RP (inactivity, lack of communication, lack of cooperation, lack of understanding, etc.). But creating a world with another person or other people when all are interested and passionate about the subject is just as exciting, it's just different than reading a book.

I don't know if my response sufficed as an answer to the question...I kind of ended up rambling >.>