Although I have included them in the count, some books are texts that I have read before. I have not considered them for my best and worst list since they are already among my favorites and have been numbered on lists past.
Here are my lists. I present them with no justification. If you would like to argue for or against any of them, please feel free to do so in the comments section. I doubt this will happen, of course, but the option remains open.
Five Best Fiction Books:
1. Ethan Frome--Edith Wharton
2. Long After Dark--Todd Robert Petersen
3. Mrs. Dalloway--Virginia Woolf
4. Tinkers--Paul Harding
5. Song of Solomon--Toni Morrison
Five Best Non-Fiction Books:
1. Blue Latitudes--Tony Horwitz
2. The Joseph Smith Papers: Journals, Vol. 1, 1832-1839
3. Evolution: The Remarkable History of a Scientific Theory--Edward J. Larson
4. A Short History of Nearly Everything--Bill Bryson
5. Hooligan: A Mormon Boyhood--Douglas Thayer
Five Worst Books:
1. March--Geraldine Brooks
2. Abraham Lincoln: Vampire Hunter--Seth Grahame-Smith
3. Breaking Dawn--Stephenie Meyer
4. The Guinea Pig Diaries--A. J. Jacobs
5. Of Mice and Men--John Steinbeck