I get a lot of odd looks when I tell people that I am a Slytherin, not only because I've just given away the fact that I am subscribed rather dedicatedly to the world of Harry Potter, but also because to belong to Slytherin House is to be dubbed as "evil."
For those of you who are less familiar with some of the Harry Potter lingo, Slytherin is one of the four houses that students attending Hogwarts can be sorted into (the other three being Gryffindor, Ravenclaw, and Hufflepuff.) The four houses each represent different values each student may find important: Basically, those in Gryffindor value bravery, those in Ravenclaw value intelligence, those in Hufflepuff value kindness, and those in Slytherin value the ambitious and cunning.
I would like to address this negative stigma associated with Slytherin House. In the Harry Potter series itself, several - if not most - of the "bad guys" are Slytherin. The heroes and heroines of the story belong to the other houses, but there seems to be a serious lack of morality coming out of Slytherin. What I want to get across is this : While yes, some of the characters in the story coming out of Slytherin are "bad guys," this does not make everyone in Slytherin bad.
It is true that Slytherins value ambition. However, it is important to not confuse ambition with selfishness. To be ambitious is to be willing to do anything to achieve your goals; to be selfish is to care only for yourself. While Slytherins are prepared to go the distance for what they want, this does not make them all sociopaths. They are capable of empathy, they have friends and family too.
Another issue Slytherins face is their stark contrast to the hero of the story, Gryffindor House. Harry Potter himself belongs to Gryffindor, so it is easy to see how one could associate goodness and the "winning team" with Gryffindor. This is one of the most blatant reasons society (and by society I mean those who are really into Harry Potter) considers it an honor to belong to Gryffindor and shameful to belong to Slytherins. Slytherins are interested in their own personal goals and whatever means it takes to get there; Gryffindors are interested in making sure the way they achieve their goals is the bold way. Slytherins are cunning and calculating; Gryffindors are courageous and daring.
The point I am trying to make here that there is nothing wrong with either of these approaches. Slytherins may be ready to do whatever necessary to achieve their goals, but that doesn't make them bad. Gryffindors may be loyal and believe in "the honorable thing," but that doesn't make them good. Horace Slughorn was a Slytherin and fought valiantly for Hogwarts against the Death Eaters. Peter Pettigrew was a Gryffindor and sold his best friends out to Voldemort. To quote one of my favorite characters, Sirius Black, "The world isn't split into good people and Death Eaters. We've all got both light and dark inside us. What matters is the part we choose to act on. That's who we really are."
We are all capable of good and evil. It is not where we come from, whether we are mudbloods or purebloods, or what house we are sorted into that makes us who we are. It is up to us and the choices we make.