I dunno why but nothing recently has been grabbing my attention at all, I've been reading Kingdom for quite some time, I like it a lot and used to read 4-5 volumes at a time, now I can just barely finish 1 volume at a time.

But basically, it's not an objective recommendation, but something very subjective, I ask you to recall anime or manga you couldn't peel your eyes out of. For me, it was Ashita no Joe, especially Carlos Rivera fight and Kaiji's Bog (read entire part in a single day), I remember entirely forgetting world exists when I read those, partly because I was down on my luck and probably related to the characters in some way.