As pointed out by Bulen_yusuf there's a website called Opening Hooks. It contains (at the moment) 247 opening lines/paragraphs from books. You're more than welcome to add your own. I'm going to through my books tomorrow and see if I can't find some to add to the database.
Meanwhile, here's some I've picked out:
Anna Karenina by Leo Tolstoy:
“Happy families are all alike; every unhappy family is unhappy in its own way.”
A Christmas Carol by Charles Dickens:
"Marley was dead, to begin with. There is no doubt whatever about that. The register of his burial was signed by the clergyman, the clerk, the undertaker, and the chief mourner. Scrooge signed it. And Scrooge's name was good upon 'Change, for anything he chose to put his hand to.
Old Marley was as dead as a door-nail. ”
Cool stuff! :D