Did you read A Discovery of Witches by Deborah Harkness? Fun and a great vampire/witch plot line! It is an adult book, but still very fun and a quick read.
I also just read A Fault in Their Stars and it is witty and funny but incredibly sad and poignant. Little Bee is another incredibly sad but poignant novel. It has great depth but provides moments of comic relief too.
For a good mystery, I really enjoyed The Body of Christopher Creed - my students enjoy this piece too. Other good YA novels that I enjoyed: The Book Thief by Mark Zusak, Twisted by Laurie Anderson, and The Hunger Games by Suzanne Collins as someone else suggested.