Gryffindor
Students who are sorted to Gryffindor value courage which has lead to their reputation for pointless bravery or even foolishness in the face of danger. Gryffindors usually want to be noble and chivalrous as well, but the definitions of these concepts can vary among the members of the house.
Hufflepuff
Despite, or perhaps because of a reputation for being the "leftovers" of the school, Hufflepuff is the most diverse House at Hogwarts. Hufflepuff's most distinctive traits are loyalty and a good work ethic, so it's no surprise that the members of this house tend to go far in life.
Ravenclaw
Known for intelligence, wit and learning, many Ravenclaws believe themselves to be smarter than the other houses, however this is not always the case. Most are sorted due to a passion for knowledge and it's possible for anyone of any level of ability to end up in this house.
Slytherin
Known for years to accept only the purest of students, nowadays fewer and fewer students are sorted into Slytherin based only on their blood. Most Slytherin students are sorted for traits such as ambition, cunning and guile. Despite this, Slytherin still retains a reputation as the dark house of Hogwarts.