The NYT's 6th Floor blog has posted a very good selection of excellent sentences. You'll have to read their selection for sentence of the month yourself but as a teaser here is something they include in the post (even though it's more than one sentence). It's by Flann O'Brien:
Misadventure fell on my misfortune, a further misadventure fell on that misadventure and before long the misadventures were falling thickly on the first misfortune and on myself. Then a shower of misfortunes fell on the misadventures, heavy misadventures fell on the misfortunes after that and finally one great brown misadventure came upon everything, quenching the light and stopping the course of life.
Misadventures and misfortunes have never sounded so joyful.
