My answer would depend on what kind of survival you're likeliest to be doing. For short-term, get-found-quickly survival, I'd recommend Cody Lundin's 98.6 Degrees. This book addresses the common survival-situation scenario of the person out in the wilderness for whatever reason who happens to get lost, get injured, etc., and focuses on getting found before any irremediable damage gets done. I've heard that most survival situations occur, not when the survivor is out on a 10-day backpacking trip, but when a little day-hike or fishing trip, etc., is unexpectedly prolonged or complicated by an ankle injury, getting lost, etc. In this situation, food is less important than signaling, and things like chipping arrowheads to bring down deer and building log shelters are not much help. He focuses you on building a basic kit that is small enough to carry with you, and multiple means of signaling.
For longer-term aboriginal-living kinds of scenarios, the best I know of is Larry Dean Olsen's Outdoor Survival Skills. That will cover your flint-chipping, kill-elk-with-an-atlatl needs.
In between fall some other books, some very good. I greatly appreciate the much-mentioned Wiseman's SAS Survival Handbook. It is one of my favorites. The Collins Gem edition, available from Wal-Mart's website for way cheap, is very tiny, not much bigger than a cigarette pack, and thus wins on portability. There's probably no excuse for not keeping a copy in a bug-out bag, your car, your wife's car, etc. It's also pretty comprehensive, though some of the illustrations didn't survive the translation from the larger version in any intelligible form. Lots of good, basic stuff, with plenty that is applicable in most places where you might find yourself. One minor downside is that Wiseman's attempt to cover a vast geographical range sometimes leads him to exceed his knowledge--for example, I seem to recall (my copy I keep in my car, so it's a hundred yards away just now) that he omits some common food uses of some of the most-common plants from my area, even though he makes mention of other less-helpful survival uses of them. This is not to run Wiseman down, but one guy just can't know everything. Which brings us to another point: it's best to find a survival guide that focuses as much as possible on areas in which you're likely to be surviving. All the techniques for getting water out of a jungle vine, repelling sharks, and building igloos will do you no good in a desert. That's one point in favor of Lundin's book: he lives in Arizona, which has everything except jungle in it (and a few that might almost pass for jungle), from lowland dune desert to alpine permafrost. Mors Kochanski's Bushcraft seems great, but his geographical focus seems to be Canadian forests--good stuff, but if finding water is your hardest problem, you'll want to look elsewhere. Richard Harry Graves' 10 Bushcraft Books has very good materials with lots that is of general applicability, though you'd find it most at home in jungle-covered parts of Australia, where Graves lived. The 10 Bushcraft Books are out of print, but some kind soul has made them available in their entirety online at
http://tions.net/CA256EA900408BD5/vwWWW/outdoor~03~000 . If you want a paperback version of it, check the online used book sellers like Amazon or
www.abebooks.com for Graves' book Bushcraft: A Serious Guide to Survival and Camping, which seems to contain most of the material in the original 10 Bushcraft Books. Tawrell has a lot of interesting stuff, and I find it an interesting read, but I have sometimes questioned his accuracy on some points (which I'm having trouble remembering).