I think my first real experience with an online community was the RuneScape member forums. After that, GameSpot, then RoosterTeeth. Lots of made-up compound words, now that I think about it. Then there was reddit, which dominated my online community experience for about six years.

I don't think I could pick a favorite. They all hold a special place in my heart. GameSpot, though, triggered my atheism. I grew up religious and had few doubts until I made an agnostic friend in real life. Even then, I held on. It wasn't until, in what ironically seems like an act of God, someone on GameSpot invited me to some sort of atheists' group. I'll never know why that was the moment that made me think, "Wait, is this valid?" I started researching and over the course of a few weeks, fell completely away from my faith. Been an atheist ever since.

So if I had to pick one that influenced me the most drastically, I'd have to go with GameSpot just for that one reason. The rest changed me in countless ways as well, but never in one particular issue.