From EthanZuckerman.com:

Marriage, as it turns out, is an extremely good predictor of happiness. Married people make more money per capita, eat better, live longer, have more sex and enjoy it more. In terms of comparisons of happiness, you’d need to be making $100,000 more as an unmarried person to be as happy as a married person. (On average, and your mileage may vary, of course. And please, keep in mind, this is Gilbert talking, not me.) Is this a causal relationship? Maybe happier people are simply more likely to get married? That’s true, but studies over time reveal a very common pattern — people are less happy before marriage, experience a happiness peak shortly after marriage, and become slightly less happy a few years into marriage, though remain significantly happier than before marriage.

Well, that’s better news than something about marriage, after all that, making you less happy. But please keep this from the folks who are happiest of all when they’re bugging singles to shack up.