S3 Simply Social Sports League
This is a notorious choice for singles. S3 Simply Social Sports League was literally started so that singles could meet and find love while staying active, with most of their games taking place in McCarren Park in Brooklyn or in Central Park. Sounds more like a matchmaking service to me, but hey I'm here for it. Their success rate is astounding, with many marriages and engagements.
[Photo via @khloekardashian]