godkiller
"We are the Fury"
Fate/Zero. Its got that rare combination of grade A animation, authentic characters and a gripping plot that moves at a nice pace. Starts off a little slow with the first ep being an hour long introduction but once it picks up
Parasyte and Psycho Pass share the same genre as DTB. Even better if you ask me
Not much out there as good as FMAB & HxH truthfully. Those are some GOAT's but Gintama & Code Geass are incredibly well revered among the anime community for good reason. Have your 90's classics like Yu Yu Hakusho which is by the same person who created HxH, Rurouni Kenshin and Neon Genesis Evangelion probably the most controversial anime ever. If you found Nina's transformation and all the other crap the Elrics went through to be compelling, should probably give that a shot
& if you mean Rainbow as in that depressing prison anime I'd go with Gungrave which has similar themes of friendship, brotherly bonds & tragedy as well as something airing this season in Gangsta which has the same tone.
This is a credited and helpful post! I discovered Fate/Zero a year or so ago and the series revitalized my interest in anime. Parasyte is another series I heard of but didn't know the name. I'll try it along with Psycho pass, Neon Genesis Evangelion and Gangsta.