I saw this 2 weeks ago, and have already rewatched it once with my fiancé (her first time). I NEVER rewatch shows that quickly, normally it's 3 years until I watch a show for the second time. Simply put, this is the one the best, if not the best, Korean drama ever produced. It's quality shines over most US and British productions as well. The show has a stellar script, cast, direction, cinematography, music, and editing. The brilliance of Korean shows is that they are normally only 16-20 episodes and that's it, story done, no second season. This format allows many of the best series to avoid any unnecessary plotlines that are essentially filler episodes. Signal adhered to that format in a clever way by giving us a satisfying series on it's own, no filler episodes, and the entire series brilliantly intertwined, along with plenty of potential for a second season (something that is rare for Korean shows). The writer of the series is currently penning a new TV series for Netflix called Kingdom and plans to begin writing Signal Season 2 this year. Whether or not the script will return as a second season will depend on availability of the cast and director. As of now, Signals holds the #1 spot over Game of Thrones, Breaking Bad, and The Walking Dead for my all time favorite series. Signal is a must-watch if you're lucky enough to find out about it.