The only manga i read with an non traditional art style is jojo's bizzarre adventure. I would say part 5 if you want non traditional art. But i recommend the stone ocean the art style is amazing.
I heard the manga of that world war 1 witch anime. Has an awesome art style too.
I think march comes like a lion has an non traditional art style too.
Kawacy has an awesome art style.
Spoiler
(http://img08.deviantart.net/a395/i/2016/276/5/7/unknown_error_by_kawacy-dajrgjx.jpg)