I read mostly SF, mystery and fantasy. For action/adventure you might try some of these authors: William Dietz (military space SF), James F David (dinosaurs), Richard K Morgan, Jack McDevitt (space opera), Kali Wallace (AI's), Martha Wells (hilarious and dangerous sentient robots, start with All Systems Red), C Robert Cargill (AIs take over the world), Todd McAulty (Robots of Gotham), Richard Kadrey (badass man comes back from Hell), MR Carey (Zombies- The Girl with all the Gifts), Glen Duncan (The Last Werewolf).
Mystery- Garry Disher (Wyatt books- the hero is a high class thief), Harry Dolan (Bad Things Happen), Nicolas Obregon.
Some sites I check periodically for ideas are below.
http://locusmag.com/
kirkusreviews
publishers weekly reviews
Happy Hunting.