Because the writers excel at finding the emotion in every scene, every interaction. It raises the bar. Makes it more than just an action show.
Because there’s always a good balance between the case-of-the-week and the ongoing stuff. We always get character drama, story arc development and bone-crunching action.
Because of the confident nature of the storytelling, and the feeling that you are always watching one chapter in a much larger story, which will only unfold when the time is right. The show has a measured way of making specific changes in the status quo, building more and more with each modification.
Because they have managed to make Oliver a genuinely (tortured) hero we can root for, and care (deeply) about.
Because Emily Bett Rickards is impossibly cute and her line delivery means she steals every scene. She is, quite simply, a star.
Because of the skillful misdirection at key times, which means you never know what is going to happen next.
Because some of the actions sequences are take-your-breath away stunning.
Because of Caity Lotz and Grant Gustin. [9.48]