If you liked
Ga-Rei: Zero
|
...then you might like
Highschool of the Dead
|
Both are very campy action series with decent animation, and a considerable amount of fan service. Ga-Rei: Zero has a wider audience for it's service, so there's that. I thought HoTD was a lot better, but Ga-Rei: Zero stood to be stupid fun.
If you liked
Mahou Shoujo Madoka★Magica
|
...then you might like
Black★Rock Shooter (TV)
|
Both are essentially really, REALLY dark Magical Girl animes with SUPER heavy themes. If you're familiar with the TV Trope "Breaking The Cutie", that's basically what the MC of both anime go through. The're's a lot of great action in both series, great animation, PHENOMENAL scores, and some incredible, and memorable characters. If you liked Madoka, you'll probably like BRS, and if you liked BRS, you'll probably like Madoka. They're very similar, just that one is slightly darker than the other.