I'll go with The Breaker for now.
It's indeed a masterpiece lolThough I nominated Magician, Girls of Wild's, and Geukji High. I ended up voting for Magician, Girls of Wild's, and Breaker: New Waves. I couldn't not vote for a series with cover pages like it has. Those cover pages have gotten so absurdly good.
It takes me twice as long to read chapters now because I spend so much time just drooling over those things.