So far I've only found 1: Mass Effect Circular and of course its not complete at all. Does anyone have any other good ones? (doesn't even have to be finished)

 

There is Mass Effect Reloaded, although it is mediocre, even if has been updating quite regularly. I think I stopped really reading it a long while ago, although I do take a look when the new chapters come out. General opinion - meh.
As far as I recall, it had a decent start. Then again, don't take my word for it.

There was also a short fic I once started, Hiring the Right Ones, which has the Peggy Sue premise, albeit with a huge dash of AU. Not really a priority by any strech of the word, but if I'll replay ME once again (it might happen), I might write another chapter-thing.
Not that great either, I guess, and in need of some serious editing. Although I have notes with plot fitting for a long journey... somewhere.

Beside those, I'm not sure if I've seen any more. Although to be fair, I haven't seen Circular before, either.