Probably generally anything considered YA. Hunger Games comes to mind. Maybe Cherie Priest's Boneshaker, still meaning to finish that series.
I can see feeling sheepish about reading The Hunger Games in front of co-workers or something like that, but in general, its a different world we live in, so many adults reading YA so openly that it just doesn't really strike me anymore unless its something like Harry Potter or Rick Riordan -- which my brother reads with no embarrassment whatsoever.

