Anak

Ghost Hunt

"The adventures of the Shibuya Psychic Research Center as they investigate mysterious occurrences all over Japan with a team of other spiritualists and clever assistants." 

>>Really suspenseful. And I like their scientific approach to the paranormal. It is very similar to how actual paranormal investigations are being done. 

Basilisk

"The story takes place in the year 1614. Two ninja clans, Tsubagakure of the Iga and Manjidani of Kouga, battle each other to determine which grandson of Tokugawa Ieyasu will become the next shogun. The deadly competition between 10 elite ninja from each clan unleashes a centuries-old hatred that threatens to destroy all hope for peace between them." 

>> Gritty, bloody, hardcore. Not for the faint of heart. Good pacing, great animation...definitely will keep you at the edge of your seat until the very last.

Heroic Age

"The story follows the voyages of the starship Argonaut and its crew to find a means to bring peace to the universe. The ship carries the young human clairvoyant princess Dhianeila, who is on a mission to find the mythical savior of the human race."

>> Surprisingly, it is about mechas. 

Black Lagoon

"The story follows a team of pirate mercenaries known as Lagoon Company, that smuggles goods in and around the seas of Southeast Asia in the early to mid 1990s."

>> Badass pirates. 'Nuff said.

(Disclaimer: All summaries were taken from Wiki)