How to watch Attack on Titan
Attack on Titan is one of the cleanest long anime watches because all 87 episodes matter to the main story. Start with Season 1 and keep going in release order through Season 2, Season 3, and The Final Season. The only thing that trips new viewers up is the naming of the last stretch: after The Final Season Part 2, continue with The Final Chapters Special 1 and then The Final Chapters Special 2. The four compilation movies are optional recaps, not new canon material. They are only useful if you want a refresher before later seasons.