In no particular order, four books I'm looking forward to reading in 2018:
Armistice by Lara Elena Donnelly, the sequel to Amberlough.
Impostor Syndrome by Mishell Baker, the sequel to Borderline and Phantom Pains.
Revenant Gun by Yoon Ha Lee, the sequel to Ninefox Gambit and Raven Stratagem.
Record of a Spaceborn Few by Becky Chambers, the sequel to The Long Way to a Small Angry Planet and A Closed and Common Orbit.
All of these are sequels, which is why I'm looking forward to them. In my experience truly great books tend to be standalone. But of course as publishers and writers well know, trilogies and longer series are more reliable sellers because they establish expectations and create just the type of eagerness I feel for these sequels.