eharmony has a good looking, easily navigable site for people looking for that "significant other." But they go beyond the typical hit-or-miss online approach, actually suggesting the radical idea that psychological testing can help people make that decision. I strongly recommend that anyone looking for a relationship try eharmony first.

Their Matching System is comprised of a series of complex models designed to create matches between highly compatible individuals. These models work by evaluating 29 critical underlying factors, each comprised of a multitude of variables, which have been proven to predict the success of long-term relationships.

Compatibility Is The Key
Scientific research has shown that picking the right person is the best way to achieve a great relationship. But how do you make a great choice in a club, church event, or party, where appearance and small talk is really all you have to go on? Using the internet, eharmony is able to learn about its members from the inside out and match them based on deep, meaningful characteristics. Our detailed questionnaire measures the intricate facets of a person, including the 29 dimensions that are most important in relationship success. We then match singles who have the best chance of making great relationship partners. And to improve the chances of success even more, we guide matches as they get to know each other with a unique guided communication process.
With the help of eharmony’s compatibility matching and communication guidance, our members can quickly find a “soul-mate,” instead of just struggling through endless dates that lead nowhere.