I have been saying for sometime now that I believe Marilynne Robinson's novel "Housekeeping" to be the finest work of fiction of the last half of the 20th century. I'd nominate "To the Lighthouse" to be it's equal in the first half, though the competition in those decades is considerably more fierce.
"Great Expectations" has my favorite opening chapter in all of literature. Can't think of it's equal. I also love the opening paragraph of "All the King's Men."
I'm still blown away by the first volume of Peter Guralnick's biography of Elvis, entitled "The Last Train to Memphis." The second volume, "Careless Love," is quite good as well but, whereas the forces that destroyed Presley are all too familiar, the currents that created him were unique, making the "rise" in his story far more fascinating than the "fall." Cyra McFadden's "Rain or Shine" is family memoir of the highest order.
I used to read mysteries fairly regularly but I think I overdosed on them at one point and swore off. However I always make an exception for a new Peter Lovesey or K.C. Constantine.
Of children's books there are no end of riches:
"The Wind in the Willows", of course and "Treasure Island" without question, but lots of new favorites as well, including Michael Morpurgo's "Kensuke's Kingdom" and "The Wreck of the Zanzibar," Karen Cushman's "The Midwife's Apprentice," Louis Sacahar's "Holes," all the Harry Potter books, Richard Kennedy's "Amy's Eyes" and on and on. I think this really is a new golden age of children's writing and it's fun to be witness to the creations of Rowling and Morpurgo and Pullman and Yolen and many others.
When all is said and done, though, there is really only one completely perfect book, the miracle of which I contemplate on a regular basis, and that is "The Tale of Tom Kitten," by Beatrix Potter.