The Telegraph created a list of the 100 most influential books of the past decade (”The Noughties,” as they call it, or 2000 - 2009).  Somewhat appropriately — in my opinion, anyway — Harry Potter and the Deathly Hallows takes the #1 spot.  Here’s the rationale:

If you don’t know what a Muggle is by now, you’re either Rip van Winkle or enormously stubborn. This is the seventh and final instalment in Rowling’s record-breaking series about Harry Potter, the world’s most famous lightning-scarred boy wizard and his tribulations with Lord Voldemort. We’ve seen Harry grow from a spindly, messy-haired 11-year-old into a heroic young adult. Children have grown up with him, finding in his battles metaphors for their own. This volume alone sold 15 million copies in the first 24 hours after it was published. Whether wickedly skewering suburbia, or bringing Harry, Ron and Hermione into mortal danger, Rowling is never less than absorbing. Some may sneer at her books, but they are triumphant sagas about the defeat of evil that tap into our basic hunger for stories. Most importantly, she makes reading a 700-page book seem easy. This one even has a quotation from Aeschylus as its epigraph. It stands as a cornerstone of the decade, a melding of high and low culture that appeals to all ages and nations.

A very fair write-up.  Remember, it’s the most influential books, not necessarily the “best.”  By sales alone, Deathly Hallows almost has to top it.