Heads of the school student body CLOSED BY ORDER OF HEADMASTER MAJERE
The trophy room contained a list of Head Boys (and presumably Head Girls). The Head Boy and Head Girl are in charge of the prefects and should be an example to the other students. Head Boys and Girls also had the special privilege of being able to use the Prefects' bathroom. At the beginning of the school year the Headmaster appoints, new prefects as well as one Head Boy and one Head Girl from all of the seventh-year students. It is presumed they have all prefect powers as well. They're supposed to wear the badge on their school uniform. The badge would have the letters 'HB' on it.
Head Boy (CLOSED)
Head Girl (CLOSED)
Prefects CLOSED BY ORDER OF HEADMASTER MAJERE
Prefects are allowed to take House points away from other students as penalty for breaking rules, but they are not allowed to take points from other prefects. They also patrol hallways to ensure that other students are not breaking curfew. There is a bathroom with a large, pool-like bath on the fifth floor of Hogwarts Castle that is reserved for prefects and Quidditch Captains. It is located at the fourth door to the left of the statue of Boris the Bewildered. Prefects are given a badge; the colours are the colors of the prefect's House. They're supposed to wear the badge on their school uniform. The badge would have the letter 'P' on it.
Gryffindor Prefects (CLOSED)
Hufflepuff Prefects (CLOSED)
Ravenclaw Prefects (CLOSED)
Slytherin Prefects (CLOSED)
Quidditch Captains
A Captain, or Quidditch Captain at Hogwarts School of Witchcraft and Wizardry is a student and member of a House Quidditch Team who is appointed to be in charge of his or her House team. Head of Houses appoint one member of their House Quidditch Team to be the Captain. The student would presumably continue to be Captain until he or she graduates. Captains are required to organize, hold Quidditch trials, and plan training sessions for their House Teams, and are also responsible for almost anything regarding their House Team activities and members.
Captains are also given equal status as Prefects, and are also allowed to use Prefect bathrooms, ride in the Prefect carriage on the Hogwarts Express and other things. However, unlike Prefects, Captains are not allowed to dock points. Captains are generally responsible for their Quidditch team and duties only. Captains are given a silver badge to wear on their school uniform, and on their Quidditch Robes when they are playing in a match or practicing. The Captain's badge is suspected to have the letter 'C' on it for 'Captain',
Gryffindor Quidditch Captain (Andrew Thompson)
Hufflepuff Quidditch Captain (Mariana Diggory)
Ravenclaw Quidditch Captain (Jamie Prophet)
Slytherin Quidditch Captain (OPEN)
by 
) Aminia has been inactive I think (:
