Re: What Fantasy/Sci-Fi book have you just finished? Please rate it...
I've recently read Crown of Vengeance, the first book in the Dragon Prophecy trilogy, by Mercedes Lackey and James Mallory. This book is a prequel to two trilogies set in the same world, detailing the rise of the Elven Queen Vieliessar of Farcarinon, the first to lead the Light against the Endarkened (which is the true names for the demonic villains in the first trilogy).
The book starts with the origin of the Endarkened in the prologue, with the vast majority of the book detailing Vielessar's transformation from a despised outcast to overthrowing the Hundred noble Houses and becoming the High King. It's a great story, but I'm assuming that it's a trilogy, not just because it's a tradition in fantasy literature, but the two authors have written two different trilogies set in the same world, and there are too many plot points not completed for it to be a stand-alone novel.