What makes Attack on Titan such a good anime

Attack on Titan (Japanese: Shingeki no Kyojin) is perhaps one of the greatest TV shows ever made. It is undoubtedly one of the most popular anime of all time, and will likely go down in history as an all-time classic.  With the show's fourth, and final season set to air this December, I thought it would be a good time to revisit this anime, and try to understand what makes