I enjoyed all of Jon Krakauer's books, even "Under the Banner of Heaven", which isn't hiking related. Bill Bryson's "A Walk in the Woods" is one of my absolute favorites. Reading it makes me think I might actually enjoy hiking the AT. I really like "The Last Season" as well, it makes me wish I had the time and money to visit the Yosemite/Sequoia NP area.
To contribute to the thread, I like the writings of Sigurd Olson. He is known more for his work in the Boundary Waters/Quetico but he is a great nature writer. Reading his works takes me right back to the week I spent canoeing with my dad in the Boundary Waters and stirs the urge to go back.
And finally, as a general comment, I have never actually finished "The Man Who Walked Through Time" by Colin Fletcher. I just can't ever get into his writing style.