Welcome to Boyfriend of Steel. This Evangelion fan fiction was a year's worth of work from a guy with a very busy schedule, who nonetheless really liked Evangelion and wanted to try his hand at fan fiction.
You can read the story here and also read more about how and why the story was written in the Writer's Notes.
Fans of NGE will immediately note the title of the story as a twist on an infamous Evangelion video game (it's actually more of an interactive story) that was released shortly after Evangelion came out in Japan. In Girlfriend of Steel, Shinji Ikari finds himself the target of the affections of a new classmate, Mana Kirishima, who is not all that she appears to be. While I wasn't that fond of the story, I liked the situation it presented and thought it would be interesting to twist it around, while at the same time covering one of the biggest mysteries of Evangelion: the disappearance of EVA Unit 04.
In any case, this story should have a little something for everyone, and especially for those who have a fondness for Rei Ayanami. I highly encourage feedback so please feel free to add to the comments page after you're done reading. Thanks!