This show evokes every emotion possible, it has great action and adventures, an original idea that is executed and built off of perfectly, an animation style that is so simple yet so beautiful, flawless continuity, a soundtrack that is to die for, romance that is appropriate for the characters and environment, just the right amount of comedy an seriousness, excellent storytelling, plot, and lore that intertwines with the characters and their backstories wholly, and character arcs that make sure almost no character stay flat.
Watching as a young kid, I loved how funny it was and watching people fight. Now that I'm more mature, the jokes and action are still great, but I can see the emotional parts better, as well as understand the characters and realize it's not just "Hero vs Villain"
I feel this is the best cartoon ever made, and quite possibly the best TV show every created. It's just so good, I probably missed so many great aspects of it in this review.