Movies: The Departed, The Prestige, Logan, Inglorious Basterds, se7en
Series: Dexter, Breaking Bad, Sherlock, Peaky Blinders,
Anime: Samurai Champloo, Yu Yu Hakusho (same creator of HxH), Fate series
Bonus: Howl's Moving Castle (movie and anime in one! lol)
EDIT: D. Gray-Man was an excellent manga (an all time favorite but will never be finished- sounds like HxH lol) and i believe the anime followed suit in greatness The 2016 version was awesome, but its a continuation of the 2008 adaptation. If you want a more shonen series, check it out.
Redline is an anime movie about racing in the future. Great animation :3
Gankutsuou (2004) anime series based on the Count of Monte Cristo so I think you'd like this adaptation. My bro loved it.