Supernatural has numerous episodes that take place in alternate universes, and one of them sees Sam and Dean Winchester existing in the same one as Batman. Although Supernatural has its share of serious episodes, the CW series makes sure to lighten the mood throughout its 15-season run. Sam and Dean’s journey has plenty of humorous moments to balance the tragic ones, and it occasionally embraces off-the-wall storytelling that helps it stand out among other great supernatural TV shows.