Those of you who don't care for epic fantasy can skip right along to the next review. Martin's book is almost prototypical epic fantasy, from the detailed world to the large cast of characters, to (unfortunately) the long wait between books. What makes this book rise above the pack is its moral ambiguity and political manueverings. None of the good guys act in ways that are entirely blameless, and neither do the bad guys sit around cackling evilly all the time. In fact, it's quite difficult at time to even tell who the bad guys and the good guys are. While the first book doesn't bring the series to any kind of satisfactory conclusion, it's good enough to earn it a place on my list, pending a satisfactory conclusion to the series.
It's looking more and more like this is the real thing. Martin's second book takes all the qualities that made the first book great and runs with them. You want political manuevering? You've got it, in spades. You want noble villains and ambivalent heroes? You've got 'em. You want unpredictable plot twists? You've got those, too. This is a superb sequel that bodes well for the rest of the series.
The commercial epic fantasy genre is one that's had, since Tolkien, certain familiar conventions: There's always an ultimate evil, and there's always a small band of plucky heroes trying to fight it. In the first book, Martin's series looked like it was going to use those same conventions and focus on the noble Starks fighting against the decadent Lannisters; but after three books, it's becoming clear that Martin has no use for stilted convention, that he's instead interested in writing gritty, realistic fantasy (oxymoron noted). While the plots of most epic fantasies would look preposterous in a history book ("In 300 AD, the noble band of heroes defeated the Dark Lord under the mountain."), the events in A Song of Ice and Fire would fit in perfectly well. There aren't plucky heroes, there aren't nasty villains, and there aren't the tedious reversals of those cliches (like Stephen R. Donaldson's anti-hero, Thomas Covenant) that often pass for originality. What this book is about is people struggling to define the fate of a nation. Some of the people are more likable than others, some of them have motives more base or more noble; but they're all recognizable people, with human flaws, human virtues, and human mortality. When I reviewed A Game of Thrones, I claimed that this series is "prototypical epic fantasy." I'm taking that back now; this is epic fantasy that breaks out of the familiar mold and blends historical fiction with fantastic elements to make something altogether different. I recommend it both to fans of epic fantasy, and to those who are bored by the conventionality of the genre.
People who make an attempt at defining science fiction (not me; I'm not masochistic enough) are frequently stymied by so-called border cases, where a book isn't clearly science fiction, but has some science fictional elements. The Saga is just such a case. It starts off with some time travel, and alien races, and psi powers, and a whole host of other science fictional props; but it quickly becomes something more akin to fantasy. In my opinion, though, it has more in common with comic books than with either fantasy or science fiction. The characters are broadly drawn, larger-than-life archetypes, the world-building is a hodge-podge that draws on various mythologies as well as science, the plot itself is grandiose, implausible, but undeniably thrilling. (And if that doesn't sound like the comic books you've read, keep in mind that I quit reading comic books before the recent spate of tragically-hip Goth books.) These are the kind of books that the phrase "rollicking adventure" was invented to describe.
Like May's Pliocene Exile books, McCaffrey's Pern novels are hybrid crosses of SF and fantasy. The backstory to the books is decidedly science fictional, but the books themselves read like fantasies. So which are they: unique science fiction, or fantasy with a tinge of SF? Beats me. Either way, though, they're enjoyable books, with an original setting and memorable characters. I very nearly starred this review, but the books just barely lack that certain spark. (And as a side note, there are more books in the series than those I have listed here. Don't read them. All the Weyrs is such a perfect ending to the series, and the later books are mediocre.