Bubblegum Crisis

In the near future, Tokyo was left flattened as a result from a great earthquake. A new city, MegaTokyo, was then recreated due in no small part from the aid of a multi-million dollar company, Genom Corp. Genom created and mass-produced biomechanical creatures called Boomers to aid in the restoration of MegaTokyo. When the Boomers began to run out of control, the ADPolice at first tried to stop them, but they proved to be far more difficult to deal with than was first imagined. Under the ever looming Boomer threat, a group of four girls from varying degrees of society banded together. Calling themselves The Knight Sabers, they were the only ones with enough firepower and resourcefulness to defend the fledgling MegaTokyo from Genom and it's berserk Boomers. (Source: Anime News Network)

Sadamitsu the Destroyer

Sadamitsu, a high-school delinguents turned to a masked-hero, while not dealing with his rocky relationship with the strong female protagonist, he puts on a motorcycle-helmet-like mask and becomes a semi-robotic superhero who fights. He is assisted by other possibly- mechanical creatures in order to save the earth from the invasion of 20,000,000 escaped alien convicts. (Source: AniDB)

Parasyte -the maxim-

They arrive in silence and darkness. They descend from the skies. They have a hunger for human flesh. They are everywhere. They are parasites, alien creatures who must invade–and take control of–a human host to survive. And once they have infected their victims, they can assume any deadly form they choose: monsters with giant teeth, winged demons, creatures with blades for hands. But most have chosen to conceal their lethal purpose behind ordinary human faces. So no one knows their secret–except an ordinary high school student. Shin is battling for control of his own body against an alien parasite, but can he find a way to warn humanity of the horrors to come? (Source: Del Rey)