I'm half way through the books and whatever is in there essentially is very different to what's on TV show... And I like them both. In the book I would not even think of a possibility of Chuck and Blair getting together, however, in the show I think that Chuck and Blair are the best couple ever! Leighton's and Ed's chemistry is undeniable and sometimes makers of the show have to go with just that-chemistry! And in my POV these two work so well together!
Im gonna say something and I know that Im in absolute minority here, but they are my absolute favourites: Serena and Nate... That's who I root for as a couple (and Chuck and Blair of course!)


