If I do recommend a book, I usually specify to whom I think it will be of interest. Rarely do I come across a book that I think will be of general interest. My experience with books is that there are so many and they are so specialized (modern books at any rate), that very few are actually of general interest. This, I think, is one of those books that one should read.
Many moons ago I was inspired to try and craft a list of 25 books that everyone ought to read at least once. It was, without any false modesty, a dismal failure. I did eventually post such a list, but it was so obviously lacking that it was embarrassing. There are just too many books that everyone ought to read. And people don't read nearly enough. I regret the time I lose to computer games and movies even though I enjoy them and think that they (or at least the movies...okay, some of the movies) have worth. It boggles my mind that people can get through a year without reading a book.
All this to say, I guess, that books I think everyone ought to read have to be worthwhile to read, have application to just about everyone as well as being well-written and accessible. There's a lot of philosophy that would be quite useful for the world at large to study, but to minds that have atrophied from steady diets of nothing more intellectually strenuous than American Idol or some other such nonsense jumping straight into Plato's Republic wouldn't do much good. I struggle a bit with it and I'm no bumbling idiot, even if I do say so myself.
Everyone ought to spend a goodly portion of their time contemplating First Things, but so few people do. Most of the books I suggest to all and sundry are books that deal with such fundamental topics.
(Edited slightly from my comment here.)
Listening to: The Boston Camerata - Nueva España - 12 - Tiento