This might not be new to anyone if you are an active Plex.tv-user. But it's news to me, so here I am, sharing it.
The Poster Database is a website collecting custom made Plex-posters for movies and TV-shows. It used to be a subreddit that became so popular they had to create this website.
I've been spending a lot of time cleaning up my Plex-library and making it pretty. My OCD loves it.