I've heard that a lot about the Mary Sues. I dunno though! Sometimes I think a lot of people automatically associate female love interest as Mary Sue and I don't think that's fair. I mean, at least with SPN you don't have those "tenth walker" scenarios, like Lord of the Rings, you know, hi, I'm the gorgeous female elf that is now apart of the Nine and falls in love with so and so, and etc. Granted there IS a good number of Really Bad Het fics in the SPN fandom, but a lot less, I think, than I've seen in HP or Dark Angel or the like. I just wish people weren't so quick to throw up those assumptions. :(