http://www.perfectmatch.com
2. Matchluv.com
http://www.matchluv.com
3. Matchmaker
http://www.matchmaker.com
4. eharmony
http://www.eharmony.com
5. Metrodate
http://www.metrodate.com
6. American Singles
http://www.americansingles.com
7. date.com
http://www.date.com
8. ePersonals.com
http://www.epersonals.com
9. Lavalife
http://www.lavalife.com
10. Match
http://www.match.com