Mitch Sisskind's candidates:
". . . an excellent blurb line is, "i put this book in my son's/daughter's suitcase when he/she went of to Harvard/Yale/Berkeley." it shows you have a family, which makes many people feel closer to you, and it also shows that you trust the book enough to put in in the hands of your kids -- in whom you have a huge financial investment.
another good line is, 'if you read only one book this year, make it this one.' Because that sort of gives them permission not to buy any more books this year. but if it's getting close to the end of the calendar year this line could look funny -- in that case make sure you say 'if you only read one book this fiscal year....' "