The kind of books I like are the dark, dystopian ones, not 1984-ish, as that's too authoritarian for my taste, but the ones where the Champions of Light don't always win; for example, I never enjoyed the Harry Potter Saga until the last books, Half-Blood Prince and Deathly Hallows, because that's where you get to learn about Snape, Voldemort and their past, though most books and series never end the way I would like to.
For example, I would have wanted Harry to find out through Snape's memories that Snape was his biological father, explaining the fact that Harry has dark instead of ginger hair, and that Snape cared for him, and have Voldemort regain his human appearance as Nagini was slain, a gradual process that should have started with the destruction of the first Horcruxes, and the darkness inside him should have gradually departed until he was finally redeemed as he once again became mortal, but Harry, consumed with anger, hate, malice and confusion, should have cast Crucio and then the Killing Curse on him, becoming the new Dark Lord and Master of Death as he would be in possession of all Deathly Hallows. Years later, he, in turn, should have been defeated and redeemed through the only means possible and through what allowed him to survive Voldemort; love. Ginny, unbeknownst to both of them, should have become pregnant with Harry's child before Harry's corruption, and his own son should have brought him back to the light once more, either through sacrifice, through combat, through his unfortunate death at Harry's hands or through conviction that Harry is not an evil man, which should prevent him from killing his son as he doesn't mean it when he casts one of the Unforgivable Curses on him.
That would have been an epic, adult saga, instead of the anti-climatic end of Harry Potter which we got instead. Sort of a Darth Caedus-esque end to the Saga.
One of the few authors I've found who can accomodate this kind of taste is Drew Karpyshyn; tales of antiheroes like Darth Bane are amazing, the focus on the social darwinism of the Sith is what distinguishes him from the authors who think the world is painted in black and white. Who else but Drew could have come up with the Mass Effect Saga? The original plot of Mass Effect 3 was to be based upon Dark Energy, a concept Drew had come up with since the beginning, and which is a real-life phenomenon, basically a form of Global Warming that will consume the galaxy unless stopped, and it was mentioned in Tali's recruitment mission in ME2, in the Arrival DLC and with Gianna Parasini on Noveria. The Reapers were originally a species who "decided" to meld into sentient machines, in order to conserve energy and be able to harvest each new species that arose, in order to incorporate their knowledge so as to be able to create a solution, which is what they attempt to do during the years they lay dormant in dark space; it is why Sovereign says each Reaper is one nation, one species, why he says we can't hope to comprehend their motives, as we would not willingly lay down our lives for this purpose, as they've learned through experience that brute force every 50.000 years is the best approach, why they leave primitive species alone, so that they can evolve, and why Harbinger's avatars in ME2 in their combat dialogue say that the experiments must go on and progress cannot be halted. The original ending was to be that you would choose between sacrificing your own cycle and species, hoping the Reapers would be able to solve the issue of Dark Energy, or destroy them and hope that the collective intelligence of the contemporary species would be enough to halt Dark Energy before the heat death of the Universe; i.e, a choice which seemed crystal-clear in the beginning becomes much less so as the game progresses, and it's a morally grey choice, both of them being beneficial and detrimental, ending in a sort of dystopian, harsh realism.
My favourite antagonists in books would have to be Arthas, Darth Bane, Jacen Solo/Darth Caedus, Tom Riddle/Voldemort and those who work behind the scenes, such as the Dark Voice and Darth Sidious.