Mary Sue and Gary Stu

The internet is a fascinating place, where you can literally find anything, including poorly written fanfiction.  In fact, reading the most infamous pieces of literature (term uses loosely) on the internet (dubbed "badfic" in the jargon of the online community) is somewhat of a hobby of mine.  Besides providing a chuckle at the poor skills exhibited in some (which may or may not be intentional, depending on whether the author is an internet troll or not), many works display the gender perceptions and insecurities of wider societies.  The Mary Sue is a common staple of online literature, especially in series that are/were perceived as male-dominated (Star Trek, Lord of the Rings, Star Wars, etc...).  These characters are glorified, always being the most beautiful, most talented (in typically feminine tasks often, such as singing and dance), most skilled in combat when action applies to the series, and most popular.  They have little or no flaws, bend the universe to their wills, and their ultimate goal is always to get the guy of their dreams.  Not only are they usually the perfect picture of femininity, but they dominate their male counterparts as well.  It is obvious in many cases that these characters are stand-ins for the female authors, as many will voice opinions held by the author.  This considered, I think it says a lot about how girls (as the poor writing quality indicates, I believe the authors are rather young, most likely preteens or younger teenagers) perceive themselves and their roles in society.  Because the characters are beautiful and popular to an extreme, it is likely that the authors are not as "accomplished" in real life, thus using their fanfiction as a chance to "improve" themselves.  The more that we flood images of unnaturally photoshopped women, the worse standard girls are bound to feel about themselves.  Ironically, the fan community reacts worse to these fabricated characters than they most likely would to the authors themselves, resulting in harsh commentary that doubtlessly affects the author as well, creating a vicious cycle of poor confidence.  I believe they also create these characters because they feel helpless in reality, hence their tendency to bend the cannon story's universe and win over their attractive male counterparts, which they may feel they have no chance of on a daily basis.  There we have the girly side of things.
The male version of the Mary Sue is often called the Gary Stu, and he only has one purpose in the story: to be the biggest badass of them all. He always shows up to beat the "bad guys" (who may or may not be villainous, as long as they're strong opponents), save the day and win all the glory; whether or not they get the girl is negotiable or a side effect of their super-macho presence.  Gary Stus are less likely to be noticed as early on as Mary Sues; it is a sad fact of life and even literature that male characters are typically more aggressive, so they are harder to spot than the usually ultra-aggressive Mary Sue who is partially defying her established gender role.  This tells me that society is exerting immense pressure on young men to be the biggest and the baddest, which not every boy can do.  Although their ideals are manifested differently than the Mary Sue, they are essentially the same dilemma: youth pressured by society to fill an ideal which is unattainable (and honestly quite undesirable) for the average human being.