You went from Studio Ghibli to Attack on Titan?
You have not given much specifics of what you want. Maybe since you might be okay with the darkness of Attack on Titan, I could recommend Death Note, I am kind of sick of the series, but it can be good for beginners who want something smart.
If you want to try something super cute and easy to watch, maybe try Acchi Kocchi.
Pandora Hearts tends to be popular among girls, got some action and mystery.
The Girl Who Leapt Through Time, is a pretty good movie.
Kamisama Hajimemashita, might also be a nice romantic comedy, or maybe Kimi ni Todoke.
Trying to look at something that matches interests, well if you like reading, maybe try Dantalian no Shoka.
_________________
Through dream I travel, at lantern's call
To consume the flames of a kingdom's fall