10/10. Perhaps the best animated series I've ever seen.
Each scene is composed with care, characters are always in motion and the background of each scene is not merely a background, but a living, breathing world with layers of detail. The animation of characters... Facial expressions are so realistic you can feel the emotions. Certain scenes convey messages without a single line being spoken, purely from expression. Furthermore, the voice acting perfectly complements each character.
Arcane is paced fast enough to keep viewer's attention, with vivid action scenes and an incredible plot, but slow enough for us to feel fully immersed in the world of Piltover. The soundtrack is also impressive and unique, further bringing the world of Arcane alive.
As a League of Legends fan, this series delivers beyond any expectation, dropping Easter Eggs hints from the game. However, people that are not familiar whatsoever with League such as friends and family who have watched, were also blown away. The story is written in such as way that allows for a new viewer to understand the plot without any knowledge of the lore/backstory. Characters that aren't in the game are given as much detail and care as those that are.
Would highly recommend this series to anyone who enjoys fantasy / sci-fi