I recently fount this gem of a series called "Bounen no Zamned", otherwise known as "Xam'd: The Lost Memories". Currently the series is still running, but once it's finished airing i highly recommend it to be considered to be included in a series vote. If not, i at least recommend others watch it too, i fell in love with it after just the first episode.

"Sentan Island exists in a state of dreamlike tranquility; a small island, surrounded by the Yuden Sea, cut off from the war between the Northern Government and the Southern Continent Free Zone. Akiyuki Takehara lives on Sentan Island along with his mother Fusa. Despite his mother's strained relationship with his father, Ryuzo, the town doctor, the bond between father and son remains strong. One day the island's tranquility is shattered, when Akiyuki, along with his best friends Haru and Furuichi, are caught up in an explosion on a school bus. The explosion produces a mysterious light which enters Akiyuki's arm. With no time to understand what has happened, Akiyuki is transformed into a creature called Xam'd. Akiyuki rampages through the city, only to be stopped by a mysterious girl who offers him a choice: come with her and live, or stay and turn to stone. Accepting her offer, Akiyuki embarks on a journey of discovery that will take him to new lands, and help him to understand the connection between himself and the life-form known as Xam'd."

The animation is extremely well done and a joy to watch, it is from Bones, the creators of series such as RahXephon, Wolf's Rain, Scrapped Princess, Eureka Seven, Ouran High School Host Club, Darker than Black, Angelic Layer and Fullmetal Alchemist. The musical score is composed by Michiru Ōshima, known for her work in Full Metal Alchemist, The music is a really important part of the series and matches the animation style and pace of the action very well as you can see from the Opening video:

http://uk.youtube.com/watch?v=9EkhbIcLAFU the song is called "Shut up and Explode" by BOOM