In today's JACS ASAP is a review of the 90th edition of the CRC Handbook. This thing has been around for so long that it never occurred to me that I didn't know what CRC stood for, until my octagenarian coworker asked to borrow my "rubber book". When he saw my confusion, he explained that the rubber book was a reference put out by the Chemical Rubber Company.
This huge tome may be the best know of all science reference books. I was actually really surprised to see a review of it. To me it seems that if you like reference information in book form, it's fairly obvious you need this book. I mean it's been out for 95 years, how could you not know about it?
As a side note, they seem pretty good about adding things to it, and seldomremoving old info. Sometimes the internet isn't the best place to find old information, but if it's chemistry and physics it's in the CRC handbook. They even take out errors from older versions. A collegue wanted to remove some water via an azeotrope that he found in the CRC. I thought it sounded like it wouldn't work (azeotropes tend to form between polar and nonpolar liquids, not polar and polar - good bit of minutiae to know), and after a little looking we found out it was a mistake that was removed from later versions.