The site's proprietary series of questions to determine users' personality traits have become a much-imitated format, and with good reason: Enough of them will give you a pretty good picture of a person, and that's never a bad idea when you're looking to date someone.
OkCupid graciously provided us with some internal data, which informed this infographic and offers a portrait of what the site's users find most attractive in each other.
Basically, you're looking at the traits that are likely to result in a higher "received message quality quotient." In other words, when Person A receives a message on the site, if Person B who is sending it has these corresponding traits, then the receiver is more likely to respond, thus sparking an exchange.
Confidence is the most attractive quality in men and women, while "party animal" ranks last for both genders. (See the rest of the preferred traits above.) OkCupid used data from 80,000 women and 150,000 men, ages 20-60 years old, so it's a fairly large and representative sample size. I'd swipe right on that.