Oh let's see. I used Match.com first, and dated a guy I met there for about a year. I tried Yahoo! after that and found a few friends, but nobody to date seriously. Tried LavaLife, too, but I wasn't all that fond of it. Didn't really meet anybody there.
I did eHarmony for a little while, but it got too expensive! I know they have that "free six months" deal, but I couldn't afford to get the first six months. :(