Originally Posted by
The One Who
Slytherin never seems to have any 'good' attributes associated with it.
A list of Slytherin traits, taken from the Harry Potter Wiki: traditionalism, resourcefulness, ambition, cunning, shrewd, leadership qualities, achievement-oriented, self-preservation, seeds of greatness (I'm not sure how that's a character trait, but oh well), intelligence, determination, certain disregard for rules.
With the exception of traditionalism, I would consider all of those 'good' attributes (and I certainly identify with them), but it really depends on how you use them. To quote from the same page:
Cunning and ambition are easily turned towards ill purposes, but are not inherently negative; furthermore, daring, intelligence, and loyalty can as easily become negative.