Taking from some of the shows I was watching, I made a few shots in the dark and compiled a small list of shows you might be interested in.
Another: Mystery, Horror, Psychlogical ( Viewer discretion advised ) A good show about a middle school class and their dealings with the supernatural. I found it really interesting and it kept me guessing throughout the show.
Baccano!: Action, Comedy, Horror, Supernatural ( Viewer discretion advised ) I am currently watching this and have only gotten through the first two episodes, but I hear it is amazing and has a similar style to Durarara in the way the story is told ( like the show heroes, where different stories intertwine with each other, to create a larger overall tale ).
Durarara: as suggested earlier. I quite liked the show, and I agree with what was said earlier about it.
Ergo Proxy: as suggested earlier. This one was a little hard to follow at times, but I got so attached to the characters (especially one of them) that I couldn't help but watch the entire thing to see what happened to them.
Fullmetal Alchemist/ FMA: Brotherhood: Action, Adventure, Drama, Fantasy ( Viewer discretion advised ) Both are really good and worth watching but if you do watch both, be aware that they only change after about 12 episodes in, so everything will look the same until then. Still amazing shows worth considering.
Mirai Nikki (Future Diary): Action, Mystery, Supernatural, Psychological ( Viewer discretion advised ) Middle school kid gets caught up in a game of a god and has to play for his life. I liked the show, but you should probably only watch this if you don't find Yandere unnerving really. There is a little bit of gore also, so if you're ready for that then this could be worth watching.
Samurai Champloo: Action, Drama ( Viewer discretion advised ) This show is amazing; imagine samurai, ronin, and badassery all in one high action show with at worst average fight scenes (most fights are fantastic). It is also funny at times, but this is definitely worth considering.
Stiens;Gate: as suggested earlier. I liked the show and its take on time travel. Definitely worth consideration.
Shows that may be more of a stretch than the others:
Puella Magi Madoka Magica: Drama, Psychological This is a magical girl anime (like Cardcaptor Sakura or Sailor Moon) but it is surprising how different from the stereotype of the series, and is definitely worth a watch if you are looking for something new. Get ready for an emotional roller coaster though; this show will evoke intense emotions if you are the kind of person to get attached to characters in a show.
Shiki: Horror, Mystery, Psychological ( Viewer discretion advised ) A different take on vampires that I think is worth watching, but the show is a little slow.
Un-Go: Drama, mystery, Psychological, Sci-fi This show is an odd one, but I found it really enjoyable and it does a good job at keeping you interested throughout the episodes, even if some of them feel disjointed.