Besides being filled with holiday cheer and the threat of pending tax bills, the end of the year is a fertile time for "Best of" book lists. No two book lists are ever the same, but each of them is worth poring over just to see if it contains any titles that you've already read, or better still, points you in the direction of your next great read.

But the creation of so may "Best of" lists begs the question: which books are the superspecial ones that have made multiple lists? Which ones are the cream of the literary crop?

Being a fan of science fiction and fantasy—not to mention an OCD geek of the highest caliber—I just had to know. So, I put on my aggregation gloves (what, you don't have your own pair?) and started crunching numbers. What emerged was an absolute, very unscientific "Best of the Best" list of the science-fiction and fantasy books that debuted in 2015.

But first, a few notes:

o Did I mention this list was very unscientific? Each list is compiled from a different set of criteria by a different set of folks, which is why no two lists ever agree.

o I used 8 different sources to arrive at the aggregate, all of them specifically geared toward science-fiction and fantasy books: Amazon, Barnes and Noble, Los Angeles Times, NPR, Publishers Weekly, The Guardian, The Washington Post, and course Kirkus Reviews.

o I only included books that garnered three or more mentions. That yielded a list of seven books, which seems like a good size. That said, I also include below a list of "Honorable Mentions" that appeared on two lists.

o The complete set of titles that appeared on all the lists combined numbered 107. That means there 100 more titles that somebody thought was worth including in a "Best of" list. It's worth a peek at the above named sources to get even more reading suggestions.

o For yet even more "Best of" book lists, head on over to the website of Largehearted Boy. For the past 8 years, he's been helpfully compiling an annual list of "Best of" lists. How's that for meta?

o I'd be interested to know your "reading average." How many of the seven books have you already read?

And now, on with the list!

SCIENCE FICTION AND FANTASY—THE BEST OF THE BEST

Ancillary Mercy by Ann Leckie (5 mentions)

With more mentions than any other book on the source lists, Ancillary Mercy tops the "Best of the Best" list. This book sees Captain Breq Mianaai finally confronting the interstellar ruler w ho blew up the ship that originally housed Breq’s consciousness. It's the third book in a mind-bending trilogy, but don't let that deter you from reading the whole series; in previous years, the first two books (Ancillary Justice and Ancillary Sword) have appeared on multiple "Best of" lists as well. They've also won multiple awards.

Three Moments of an Explosion by China Miéville (4 mentions)

There's something appealing about China Miéville's fiction that hard to describe. He's been described as a writer of "weird" fiction, which may be off-putting to someone who has never read weird fiction before (or who doesn't realize they already have read it). Suffice it to say that if you’re looking for something off the beaten path, but also wholly satisfying and enjoyable, then look for this intriguing collection of short fiction.

Aurora by Kim Stanley Robinson (4 mentions)

Robinson, the most seasoned author on this list, writes fiction that's firmly rooted in science. He’s perhaps not the best choice for science-fiction newcomers, but longtime science fiction readers swear by him. Aurora is about mankind's first voyage beyond the solar system on a generation starship with the goal of colonizing another planet. Like all of Robinson's books, it's backed up by realistic science and insightful prognos tication.

The Fifth Season by N.K. Jemisin (4 mentions)

Jemisin, at a point relatively early in her promising career yet already an accomplished writer, hits another home run with The Fifth Season. Here, in a land already too familiar with Extinction Level Event calamities, a woman attempts to find her kidnapped daughter on the same day a rift appears in the earth, turning the planet into a dying world. This is the beginning of a new series.

Uprooted by Naomi Novik (4 mentions)

Master storyteller Naomi Novik (who wowed audience with her "Dragons in the Napoleonic Wars" Temeraire series) takes to more traditional fantasy in Uprooted. The book is rooted in folk stories and legends; it's about an evil wizard who periodically forces a neighboring village to give up a young woman to serve him in exchange for his protection from evil. Page-turning and fun, Uprootedis a treat.

Slade House by David Mitchell (3 mentions)

In Slade House, David Mitchell delivers another unconventi onal but gripping story about a mysterious house that only appears if the conditions are just right. Its residents, an odd brother and sister, entice their unwary victims into the house, where they soon find out that they cannot escape. Like Mitchell's well-known Cloud Atlas, Slade House is a story that spans lots of time, in this case decades.

The Traitor Baru Cormorant by Seth Dickinson (3 mentions)

Dickinson holds the honor of being the only author on the list because of a first novel. He accomplished this by writing an inventive, richly detailed geopolitical fantasy in which a young woman from a conquered people tries to transform an empire. Genre fans love worldbuilding and this one's got plenty.

HONORABLE MENTIONS

As noted above, a few handfuls of books got mentioned on two lists, thus warranting an honorable mention:

o The Long Way to a Small Angry Planet by Becky Chambers

o Twelve Kings in Sharakhai by Bradley P. Beaulieu

o The Only Ones by Carola Dibbell

o Dark Orbit by Carolyn Ives Gilman

o Radiance by Catherynne M. Valente

o Futuristic Violence and Fancy Suits by David Wong

o A Knight of the Seven Kingdoms by George R.R. Martin

o The Cinder Spires: The Aeronaut's Windlass by Jim Butcher

o The Sorcerer of the Wildeeps by Kai Ashante Wilson

o The Grace of Kings by Ken Liu

o Wake of Vultures by Lila Bowen

o The Watchmaker Of Filigree Street by Natasha Pulley

o Seveneves by Neal Stephenson

o Trigger Warning: Short Fictions and Disturbances by Neil Gaiman

o Golden Son by Pierce Brown

o The Library at Mount Char by Scott Hawkins

o Ghost Summer: Stories by Tananarive Due

o The Shepherd's Crown by Terry Pratchett

o Sorcerer to the Crown by Zen Cho

John DeNardo is the editor of SF Signal, the Hugo Award-winning group science-fiction and fantasy blog featuring news, reviews and interviews. You can follow him on Twitter as @sfsignal.