Age-based niches: These sites are for people of a specific age. Baby boomers are overwhelmingly turning to the web to find a mate. Sites like Match.com and POF.com offer members a chance to search specifically for the age group that interests you, but SeniorPeopleMeet.com and OurTime.com are the two largest sites designed specifically for the baby boomer market.
Match.com: If online dating was boxing, Match.com would be in the heavyweight category. It is a site that has a large number of members, longevity, site functionality and pricing options. I used this site for two years while I was living in New York and had quite a few dates. Unlike eharmony though, I spent a lot more time weeding through lower quality profiles.