Ah, the Room of Requirement. Perhaps one of the most magical places in the Wizarding World. First mentioned, though not named, in The Goblet of Fire, then identified in The Order of the Phoenix, this innocuous room, that has the possibility to give you what you are most in need of, has become one of the most pivotal magical places in the Harry Potter series.Mostly people stumbles across it when they needs it, sir, but often they never finds it again, for they do not know that it is always there waiting to be called into service, sir.
It transforms itself into whatever the witch or wizard needs it to be at that moment in time, although there are some limitations pertaining to fundamental laws of magic.
I personally would use the Room of Requirement to stash my candy hoard and perhaps to take a breather in a quirt place from time to time. Maybe a hiding place after a prank would not be remiss.
So, what would you use the Room of Requirement for?