The title cards are imaginative, cool art and animation themselves and they are meant to tell the story/give a hint of the season/episode in general. When you see one you immediately know that it is Supernatural. Can't wait for the season 11 one. So in the meantime I piled up all the title cards and made another poll.
If you are interested on information about the title cards you can check out:
Supernaturalwiki - Title Cards
9.04 Slumber Party
Unused alternative title card. This was tweeted by Jared a day before the episode aired. It features the message: "This is for the SPNFamily whose dedication and love drive us to continue creating this wonderful world. Keeping up the Family Business."
What do you think season 11 title card will look like? Which title cards are your favorite and why? Did you notice from the title cards something you didn't notice before.