In your own space, share a book/song/movie/tv show/fanwork/etc that changed your life. Something that impacted on your consciousness in a way that left its mark on your soul.
Supernatural introduced me to fandom. Before it there were many shows that I enjoyed and would watch over and over, but nothing made me seek out more; whether that was spoilers, photos, interviews etc. It was while looking for something more that I stumbled across fanfiction, and then the idea of fandom in general.
Over the years my experience of SPN fandom has changed. I've gone from being an anonymous lurker and commenter, to opening accounts and posting stories, to taking part in challenges, and meeting and interacting with a whole group of people who I consider friends. This is a huge thing for me, something that I hope has changed me in a positive way, and certainly something that has enriched my life. So yes, Supernatural has left a mark, and a very big and important one too.