Re:zero is a classic that isn’t talked about a lot in America but is extremely good (and season 2 is coming out soon). Another amazing one is Neon Genesis Evangelion, that one is really deep.
One Piece. In my opinion, it is one of those animes that surprise about how relatable it is and then seeing the growth of a complete underdog to become a noticeable threat to the world. It will let you know that it is cool to be an underdog but keep rising. Best part,it is still ongoing. Watch it. You will love it