It's hard to pick a top five or ten without leaving some out so I will do my best to make the list as concise as possible.
Hands down my favorite book of 2012 is Stephen King's 11/22/63. I read this back in January and it set the bar. Although I've read a lot of really great books this year, nothing was able to de-throne 11/22/63.
There's a little something for everyone in it. History, mystery, conspiracy, time travel but what I loved most was the love story and the ode to the '50s and '60s - a time I wasn't around to witness and makes me sorry I wasn't.
The Winter Sea by Susanna Kearsley
The Shoemaker's Wife by Adriana Trigiani
At Last by Jill Shalvis
Bared to You by Sylvia Day
Madame Tussaud: A Novel of the French Revolution by Michelle Moran
The Book Thief by Markus Zusak
Gone Girl by Gillian Flynn
The Given Day by Dennis Lehane
The Secret Keeper by Kate Morton
The Fever Series by Karen Marie Moning
All Summer Long by Susan Mallery