Mary-sue

[Sarah]

A sexist term used to enforce the misogynistic ideals that female characters/authors shouldnt be allowed to fantasize or write anything along the lines of wish fulfillment. Its misogynistic qualities are exemplified in many ways, most notably being the fact that its not a term dominated by the male counterpart despite existing in a patriarchal society, as well as the fact that the male counterpart is largely undecided upon in name and also undefined (see urban dictionarys [Gary Stu] entry which has no definition but to say A Male Mary Sue, and the [Marty-Stu] entry which involves the Mary Sue definition to define it).
Its usually used on the whole to bully new authors out of writing female characters altogether, making the task seem so daunting to some that they now only write slash fictions with two male characters, also exemplifying the misogynistic qualities this term involves.

[Tina]

A female character who is so perfect that she is annoying. The name originated in a very short Star Trek story that mocked the sort of female characters who showed up in fanfiction. It usually refers to original female characters put into fanfiction, but can refer to any character.
Mary-Sues are characters who are usually extraordinarily gorgeous, amazingly talented, unusually powerful, and exceedingly attractive to whoever the author has a crush on. They often possess ridiculously fancy and pretentious first names -- Angel, Raven, Jewel, Lorelei Bianca Julia Marizza Snape -- and are very, very annoying.
Mary-Sue is often abbreviated to Sue. The male equivelant is either [Marty-Stu] or [Gary-Stu].