I still buy and read the Guinness Record book every year, because it's become like an old friend that I like to catch up with, but I have to disagree with Birch East. I like the way it has changed and brings out a fresh look each year. The changes, like holograms, 3D whatever, make it fresh every year. My nephews also are big fans of the 3D gimmick.
I do agree with the recommendation for Getting into Guinness: One Man's Longest, Fastest, Highest Journey Inside the Most Famous Record Book, the new book by Larry Olmsted about the history and culture of the Guinness World Records book. After reading his review I snapped up a copy and it is great--very entertaining and a fun read! I have read the record book for years but never stopped to wonder where it came from (Guinness Beer!), how it got so big, and how large a role it has played in pop culture, and just how crazy some of the record holders seem to be. Getting Into Guinness is the story behind the records and a fun, well researched, adult read.