I have a controversial take, I think Death Note is one of the more overrated animes. By overrated, I don't mean it is bad, it is still enjoyable I give it like a 7/10. But for a story that preaches intelligence, the characters surely weren't acting intelligent. Light gave away he was Killa in the very beginning of the series, where he killed that FBI agent who was tailing him. There was no reason to kill him.
In terms of story quality AOT wins easily wins for me. For example, in DN, after L died, they just created a duplicate character in Near lol which shows that the story was heavily dependent through the characters instead of having a balance between character and plot. AOT is one of the most well balanced stories in terms of balancing between characters and plot.
In terms of characters between Light, L, Eren they were great for me. I enjoyed them all but I will give Light the advantage.