I have often marveled that the main trio in Harry Potter books, plus Neville, represent the four houses perfectly, despite all being in Gryffindor. Ron is a true Gryffindor, Hermione Ravenclaw, Neville Hufflepuff, and Harry Slytherin. (Interestingly, I do not think this works for the Marauders, thought MuggleNet disagrees with me.) So, working on the assumption that any story with four main characters can represent the four Hogwarts houses, I set out to prove my theory. Some of these were more obvious than others, but I think my theory holds up!
One thing I learned: maaaaan, the line between Slytherin and Gryffindor is razor-fine. Also: the group leader is most likely to be the Slytherin.
The Lord of the Rings (hobbits)
The Three Musketeers
Mary Anne: Hufflepuff
Dracula (Lucy and her suitors)
Dr. Seward: Ravenclaw
The Fantastic Four
Reed Richards/Mr. Fantastic: Slytherin
Sue Storm/Invisible Woman: Ravenclaw
Johnny Storm/Human Torch: Gryffindor
Ben Grimm/The Thing: Hufflepuff
The Wizard of Oz
Tin Woodman: Hufflepuff
Cowardly Lion: Gryffindor
Those four fit so perfectly that I think I’ll end there. Can you think of any others foursomes who fit the pattern (or who don’t)?