Best online dating site hands-down. Great interface, app for every phone, incredible match-making algorithms based on questions you answer. FREE! I have to disable it from time to time because it gets too addictive :)
I've actually been on a couple of dates through OkCupid. Successfully found a few good friends that I still keep in touch with to this day. I absolutely love the tests and "improve matches" options. Cons: Quite a bit of them do not post photos. Seriousness is rarely factored in. Large quantity of user-created quizzes, many that fall short.