HxH is a shounen with a lot of elements coming from seinen (complexity, deaths, negative emotions & outcome,...)
And it's IMO also true about Shingeki no kyojin & FMA
So, following my own perception, the only "true shounen" here are Gamaran & Naruto. Even if as a whole, I should vote for Naruto, the manga disappointed me too much post-timeskip. I had very high expectations which were not met.
I had not high expectations for Gamaran but those unexpected expectations were met !!! Plus, everyone knows about Naruto & I feel that Gamaran deserves to be well known as well.