There have been 178 episodes of “Adventure Time,” as of Dec. 4, 2014. While the show has evolved over the years, slowly developing a continuity and ramming Finn in to adolescence, the quality has been unswerving. In fact, many of the best episodes come in later seasons. Created by Pendleton Ward and produced by Frederator Studios, “Adventure Time” still has a bright future ahead. With luck this round-up of the best 20 episodes of “Adventure Time” will be outdated in a few years.