I was a member of It's Just Lunch. It's pricey but it did deliver what it promised, unlike Two of Us which takes your money and doesn't deliver. If you've got the dollars try it, but if you're not rolling in dough, pass on it and try Eharmony, Chemistry or Match.com.
I always suggest enrolling in 2 or more services. Skip the free ones if you're looking for a serious relationship.