I have a 1975 (a late "classic" edition) and a 1997. I have no plans to acquire a 2006, though I'll be happy to flip through it if I ever come across it at a second-hand shop or flea market. The 1997 has superior recipes for pizza crust, pancakes, and contemporary hors-d'œuvres, plus a handy but incomplete index of nutritional information for common ingredients. On the other hand, the 1975 has better recipes for the mother sauces, the very familiar mid-century American cooking I grew up with, and home-canned foods (though they must be cross-referenced to the Ball Blue Book or a recipe through the National Center for Home Food Preservation -- in the late 1980s, the USDA did a bunch of testing on old-timey recipes and found that many or most foods needed longer processing times than the old cookbooks and the government's own publications prescribed. Recall that in the olden days, jams and jellies were simply poured into jelly glasses and weren't even processed in a boiling-water bath (PDF, 1957); and instructions for tightening old-style caps are exactly, 100% opposite wrong from the way modern lids are handled ((PDF -- do not use the processing times in this publication, and do not can strained/puréed pumpkin).)
But I digress, and I've begged the question as to why you would have any Joy on your bookshelf in the first place. The wise urban home economist should have basic food preparation skills, recognize and be able to use a wide variety of foodstuffs, and know her way around the kitchen. This is because one of the easiest and most effective ways to control your household's budget is to prepare as many of your meals as possible from scratch. At breakfast, avoid boxed cereals; pack your lunch to work; and make dinner at home. Similarly, when you come across a food item on deep discount at the grocery store or farmers market, you should snap up as much as you can carry, knowing that when you get it home you'll know how to cook it up or preserve it without wasting any. You need to have a reference on hand. Without booting up the computer to watch shaky videos, learn how to dice an onion; learn how long and at what temperature to bake an ordinary casserole; and learn how to bake Parker House rolls.
Bittman's How to Cook Everything may suffice. I'm not convinced I need to get that, since I already have the two editions of Joy and a handful of specialty cookbooks that cover my household's needs. Your household's mileage may vary.
Or go seriously old-school, and pick up a Fannie Farmer -- that is, the Boston Cooking-School Cook Book, one of the first if not the first American cookbook to use standard measurements instead of "take a handful" of this and "add a tea-spoonful of saleratus" that. Oh, wait, here are her instructions for canning rhubarb (about 4/5 down the very long page):
Pare rhubarb and cut in one-inch pieces. Pack in a jar, put under cold water faucet, and let water run twenty minutes, then screw on cover. Rhubarb canned in this way has often been known to keep a year.Rhubarb "canned" this way will likely spontaneously ferment into tutti-frutti.
So where does that leave us? Older Joy of Cooking good; older canning recipes bad. Newest USDA-based home food preservation publications good; newest Joy bad. My point, and I did have one when I started writing this, is that the urban home economist should have an all-purpose cooking reference on hand, and you really can't go wrong with a Joy of Cooking, especially the pre-2006 editions. What's your household's go-to kitchen reference book?