OK Cupid

What they say:

"OkCupid is the fastest-growing, most effective dating site ever, because it is powered by a matching system the users invent.

Best of all, it's 100% free. Signing up takes less than two minutes and requires only the most basic personal information.

We offer a fresh take on online dating that will perk the interest of those bored and unsatisfied with their current options. Our users are matched with tests that are actually fun to take and users are allowed to add their own tests. The user-generated tests provide amazingly accurate matches"