To be honest, it's still going to be the creation of Chronicles of Pokemon (assuming different forums count too). Fifteen thousands posts and most popular of it's wake. Changed me a lot, made me open to different communities.
The only problem was that, once it died, I was only left with a dim light. And this is why any follow-up roleplays failed - I failed to generate a spark it had.
Otherwise, if only TCF posts count... meh, I don't have any achievements. I mean, posts, reactions and even time spent aren't that good marks of progress to me to care about.