Opening Hooks is a site/database of opening sentences to novels. You can contribute your favorite book beginnings to it and rate (from 1 to 5) the books already in the database. There are about 20 book beginnings up so far. Of the ones offered so far, my favorite is from Richard Matheson's I Am Legend (but I'm a sucker for last-man-on-earth books):
"On those cloudy days, Robert Neville was never sure when sunset came, and sometimes they were in the streets before he could get back. If he had been more analytical, he might have calculated the approximate time of their arrival; but he used the lifetime habit of judging nightfall by the sky, and on cloudy days that method didn't work. That's why he chose to stay near the house on those days."
