As of this point so far, the "Glass Sword" by Victoria Aveyard is a great book, I have read this year. I would recommend this book, to anyone who's undecided what to read or buy.

Any books in the Vampire Hunter D series. THESE books are listed under supernatural horror, but they are not at all scary.

A Net of Dawn and Bones by C. Chancy, plus anything else she writes. As reference, anyone who reads fanfiction may recognize her as Vathara ff.net and AO3 and Crossover Queen on wordpress. She is an amazing author who writes in a wide variety of fandoms and has only recently started publishing original work. Seriously, go read her stuff!

The Name of the Wind is a must read for anyone who like fantasy.

Daniel Silva for modern thrillers with actually interesting backgrounds and side-notes into stuff like art history.
Wen Spencer for fantasy or sci-fi or urban fantasy with clever and engaging characters.
Patricia McKillip for lyrical fantasy stories of self-discovery and magic; lots of subtleties in her work.
P. G. Wodehouse for hilarious light comedy in a historical setting. Typically minor mystery or romance is involved.
Garth Nix for fun young adults, particularly the Abhorsen/Lirael/Sabriel stuff.

Others later, off to go read more now.

My niece recommends the Kingdom of Fantasy series. It is about a Gentleman Adventurer Rat. She says the main guy's name is Sweet Dreams Cradle. The rat is a boy. OH, I misunderstood. The Rat's name is Geronimo Stilton.

One series I really enjoyed is the Beautiful Creatures. Prequel and sequel to it. Its fiction. Adventure. A bit of romance. Fantasy.

The Alex Cross series by James Patterson. Detective story. Following him and his life through the trials he faces with life as a cop.

Anything by Danielle Steel. Most pure romance fiction I find is horrible, but Danielle Steel's novels are just all kinds of good.

I've recently discovered a couple of new authors I like a lot...

S K Dunstal does the "Linesman" trilogy. Sci-fi, and wonderful.

Colin Cotterill does the "Dr. Siri" series. historical fiction with a touch of fantasy; it's unique in several ways. First, "historical" in this case is just the mid and late 1970s. Which frankly confuses my personal odd labels of "history" because I tend to think that anything happening recently enough that people still alive today remember it is not really "history".... but of course it is. Very good for me to get that odd mental assumption overturned! Anyhow. So. Set in the mid and late 1970s. Also the protagonist is a man in his 70s! Also the fantasy elements are more cultural beliefs given a reality that affects even the unbelievers. Oh. Set in Laos, also unusual for English-language novels.
ANYHOW. They are mysteries, and while they are not set against the happiest of time periods, they are also still comedic.
Lovely writing.

Ehhhh, couple others but I forget.