I don't know that I could limit my mystery/thriller list to five finalists, but these five books made the list:
Megan Abbott, Bury Me Deep (Simon & Schuster)
David Ellis, The Hidden Man (Putnam)
Attica Locke, Black Water Rising (HarperCollins)
Val McDermid, A Darker Domain (HarperCollins)
Stuart Neville, The Ghosts of Belfast (SOHO Press)
I've read four, all but "The Ghosts of Belfast", which is on my to be read pile. As a devoted McDermid reader, I'm going with her, but all were exceptional in plotting, characterization and dialogue.
Aspiring crime fiction writers could learn a lot from these artists.