In Tim's defense, Poor Richard's Almanac isn't terribly influential anywhere else in the world other than the United States, and unlike most of the works it's being judged against, it neither created entire fields of study nor overturned generations of thinking. In a draft of the greatest most influential books in the history of the world, it's about where it belongs IMHO.In the Almanack is so "brilliant", it deserves more than a measly 5 points. It simply paved the way for newspapers and journalism and "America" as it came to be known. It was published in Philadelphia when almost all important literature and reading material came from England or Boston. All Americans knew of Franklin and his Almanack. And you give it 5 points...Sheesh.....mMaybe I'll havbe to become your second arch-nemesis afterall...Nonfiction 6 Points
Oxford English Dictionary
Roget’s Thesaurus
World Almanac
The Encyclopedia Britannica
Poor Richard’s Almanack
I wasn't sure how to rank these against each other, so I put most of these works here. There are two exceptions which are more notable in terms of history and so deserve more recognition. All of these works are incredibly important, though the Internet has probably caused my generation to be the last to have used them on a regular basis. Ben Franklin's book deserves special mention here because it's so brilliant.