I'm not that much into anime, but my favorite ones were Naruto and Deadman Wonderland (but sadly that one wasn't finished), and, if you consider it an anime, then my most favorite one was Avatar the Last Airbender
I really enjoyed 'Elfen Lied', it has a few gory/graphic scenes, which is cool if you're into that, but the storyline is also pretty cool and touching. 'Attack on Titan' is REALLY good, the anime is awesome it follows the manga very well so after finishing the first season/second depending on when you start watching, you can always just continue the story by jumping in, in the manga. I also really, really enjoyed 'Corpse Party' it's only a few episodes long so you can easily finish it within a an hour or two. Since you like gore I'm sure you'll like it. It's also more of a horror anime, not sure if thats your thing though. I think it's worth a try though.
Watch Another! (the anime is called Another) If you like gore/horror you'll probably love it, it's my favorite of all time. Seen it 4-5 times and still love it I also have a place in my heart for Tora Dora and Aoi Hana ^^