I have to definitely say that the Fifty Shades of Grey series I never thought I would like, but ended up liking. I have to admit, though. It was explicit, in both a lot of swearing and explicit descriptions of just how Christian Grey was going to "dominate" Ana. It is most definitely not for kids. And any adult who thinks nothing of the "Warning. Mature audience. Erotic Romance" label on the back and gets it for underage readers is in for quite a surprise when that person starts spouting things like "Dominant", "Submissive", "Rough sex", etc. This series involves S&M, BDSM, etc, more or less rough sex with toys, etc.
Another was Paradise City by Lorenzo Carcaterra. When I first read it, it was actually kind of boring. But I went back and read it again and it turned out it was really interesting. For those not familiar with this title, Paradise City tells the story of a Naples police officer named Giancarlo LoManto who arranges for a temporary transfer to the NYPD because growing up, he lived in New York with his kid sister until their father was gunned down by a mob boss. When his niece is kidnapped, it's discovered that a form of organized crime from Naples called the Camorra is behind the kidnapping and the new boss is secretly Giancarlo's half-brother, which he later realizes
