Depends on what kind of relationship you’re looking for. There are all kinds of dating sites now, though I only recently found out that there are sites where people are mostly looking for long-term stuff, and sites where people are more into one-night stands. Some people are totally cool with that, and there are even guides like
Meet Single MILFs: Your Go-To Guide for Successful Encounters that give some pretty solid tips. But some people, like me, are more used to classic dating where you actually hope to keep in touch and keep things going, so I can’t say I have a favorite dating site, but I do like the ones where people want to keep things going.