Action packed, hm? Well I have a few anime, lots more manga but I'll restrict it to anime unless you want manga too.
You've already watched Brotherhood it seems, excellent one indeed. Mirai Nikki is great too. As for other suggestions:
- Accel World
- Angel Beats!
- Baccano!
- Buso Renkin
- Code Geass (I see you haven't finished it, I promise you that it gets a lot better. It's not fixated on the action but there's still lots of it and the story is fantastic. Picks up around episode 4 and I gave it a 9 at episode 14. Wasn't till R2 that I gave it a 10 though)
- Darker than Black
- Durarara!!
- Eureka Seven and Eureka Seven AO
- Fate series (Stay night, Unlimited Blade Works, Zero)
- Gurren Lagann
- Mahou Shoujo Madoka Magica
- Star Driver: Kagayaki no Takuto
- Sword Art Online
As for similar to Mirai Nikki, Deadman Wonderland is very close. I only read the manga for it though so I don't know how the anime is. Reportedly Higashi no Eden and Btooom! are similar but I haven't seen those. Monster is like a less supernatural more plot-oriented Death Note and Jigoku Shoujo is supposedly similar to Death Note as well.