I read the reviews on the back of books when I buy the books (usually just for kicks, and to see how many of the quoted authors I've read) and I've noticed that a lot of authors are called "The next ______." In days gone by, that blank used to be filled with Tolkien's name, but lately I've seen it filled with others. The two most common are Robert Jordan and George R. R. Martin. It strikes me as a bit funny. Those two are very obviously considered the "greats" by fantasy fans, but they've each only written one epic series (and not much else, IIRC) - and neither of those series are finished (in fact, Jordan died before he could complete his). And yet, they're still considered the greats, even though the work they're famous for could still end appalingly, and we have no idea. So I'm kinda curious - why do you all think those two in particular are the "greats"? Do you consider them great? Who else would you name, sci-fi and fantasy? And why? What makes particular SFF authors great? And does popular = great?