Gryffindor: taking it- they take charge of the country themself, believing that they can do a better job than the previous ruler

Ravenclaw: being named for it- the people sat down and decided they'd be the best ruler after the old one died with no heir

Hufflepuff: earning it- years of good service lead the old sovereign to pass it on to them

Slytherin: inheriting it- it is their birthright, and they have been trained for a long time in the ways of the court