The Story of English: Companion to the PBS TV Series - Robert McCrum, Robert MacNeil, William Cran
This was the text for one of my very favorite college courses of all time - The History of the English Language. It combined everything I love - words, history, literature. I can't recommend this and the 9 part BBC companion series enough. It is one of the only documentary series I can think of that I would love to own. Luckily I do own the book and I refer to it constantly.