I just watched Attack on Titan, what should I watch next?

I've heard that recommendation threads for Attack on Titan have kind of become a meme for this sub, but I'm looking for a similar vibe to AoT. So here are my thoughts on Attack on Titan, and what I'm looking for, and would love some recommendations.<br><br>Overall, it's an amazing show and I'm glad I watched it, but I really wasn't a fan of the last arc. Armin was my favorite character and he was kinda shafted near the end (and uh, those birds lol). Eren was by far my least favorite, and I was really annoyed when he became the center of the show. I thought the animation was really high quality, the soundtrack was really good, and the characters were all interesting. I liked the way it used gore, and thought it had great pacing. I would have liked to see a lot of the supporting characters fleshed out a bit more, but for the most part I thought it was well done.<br><br>So, what I'm in the mood for is something dark and gritty, a little violent, and with a lot of high stakes action. I'm not often picky about the genre, but I think I'd prefer something a little more sci-fi oriented, possibly post-apocalyptic as well. I also tend to prefer shows with really well done soundtracks.<br><br>Overall, I think I'm looking for something like Claymore, but a bit more fast paced. Anime recommendations welcome!