As a relative newcomer it is hard to believe that the site has been around that long, or that ebook readers have. So many years I spent ignorant. So my favorite forum has to be Reading Recommendations, especially the sub-forum Book Clubs. It has introduced me to so many books that I would never otherwise have known of and induced me to read many fine books I would never have cracked open downloaded and displayed otherwise.
I really don't have any ideas about improvements. This site has been a great resource since the day I was first steered to it.