I'm reading two (one at home and one on-the-go):
The Sultan's Wife which is a really rich and layered read.
On the Island has such a fun premise that I couldn't resist picking it up: 30 year old teacher is marooned on an island with her 16 year old student. From the book description:
At first, their only thought is survival. But as the days turn to weeks, and then months, the castaways encounter plenty of other obstacles, including violent tropical storms, the many dangers lurking in the sea, and the possibility that T.J.’s cancer could return. As T.J. celebrates yet another birthday on the island, Anna begins to wonder if the biggest challenge of all might be living with a boy who is gradually becoming a man.