I used to post on "Dogs on Acid" all the time in the mid 2000's. This was when drum 'n' bass was still a small community and the likes of Pendulum, Andy C, High Contract, Adam F, etc. would be regular posters. My proudest moment was being quoted by one of the guys from Pendulum just before they hit it big.
I usually find a forum for whatever interest I have at the time so typically don't hang around too long and I find reddit just far too vast and rapidly changing to really build a sense of community.