Gryffindor is the house of the Brave. Bravery and nobility do not always go hand in hand. Sirius Black was a snot-nosed brat in school, and Peter betrayed them. Does this sound like knights in shining armor to you? Bravery means being courageous, not being Prince Charming.
On another note- while this doesn't concern me personally, as I despise everyone from the Marauder Era but Lily and Remus- PETER IS THE W IN MWPP. MWPP. Where the hell did he go during your Marauder-era story? Hmmm? Hmmm? I don't even read MWPP stories, and I still hear scores of complaints from other authors and writers.
Ravenclaw is the house of the wise/intelligent/witty. No where in this statement does it say house of the frigid bitch. Being smart doesn't make you snobby- or did you stop reading at GOF and completely forget Luna?
Not all Hufflepuffs are sub-average losers, and it's fairly annoying to consistently see them portrayed as such. This might come as a shocker, but Hufflepuffs were *gasp* in the DA! D'you think Hermione would have gone out of her way to invite them if they were all mentally disabled? I mean, the original Hogwarts Champion, before poor Harry got shunted in, was Cedric Diggory- a Hufflepuff. An attractive, intelligent, resourceful [or he wouldn't have been chosen] hard-working Hufflepuff. That's right- the badger trumped the other three houses, until Harry got sucked in!
Slytherins are ambitious. Slytherins are cunning.
If you re-read that statement carefully, you'll notice that it doesn't say "Slytherins are heartless, perverse power-mongerers."
Yes, I am fully aware that most of the baddies are from Slytherin. But not all. Please stop writing all Slytherins to be cold-hearted, mean-spirited, elistist, bigoted, totally manipulative bastards. Slughorn should be your first clue that not all Slytherins are the same. For all you know, Kingsley, Moody or even Emmeline Vance could have been Slytherins. The fandom is churning with bad clones of Pansy, Severus and Draco. Please, mummy, make the hurting stop.
Regarding characterisations in general:
Please, please, for the love of whatever power you worship [or you can choose some random inanimate object if you don't at all, I'm not fussed] stop creating the 'ultimate' House character. Anyone with more speaking lines than Pansy is not an ultimate house character.
Draco is a Slytherin. Draco's... a bit of an elitist bastard. Draco is cunning. Draco is ambitious.
Draco uses his brains to a degree that some Ravenclaws might not, when he dreams up the Vanishing Cabinet scheme, and when he uses Crabbe and Goyle in his plan. Draco shows bravery in some of his choices. Draco proves that he is hard-working as he begins to hatch his plan.
Hermione is a Gryffindor. She shows unparalleled bravery in some circumstances, including following Harry to the DoM in book five.
Hermione is extremely loyal to her friends and cause. We all already know she's considered the cleverest witch in her year, maybe even in Hogwarts. Hermione studies her ass off in order to keep ahead and also to help Harry.
Luna is a Ravenclaw. She's smart. She has some common sense, although she might not choose to utilise it all the time. She's wise beyond her years, shown by her profound words to Harry at the end of OoTP.
Luna is brave- she rode out the storm at the DoM. Luna is hard-working- she keeps at her theories and continues to work on finding those strange creatures with her father. Luna is loyal- to her father, and to her friends, in a way that many other could never be.
I believe I covered Hufflepuff above, with Cedric.
What's this mean?
None of the characters are the sum of their houses. As Dumbledore said, it is our choices that define us. Hermione could have been in Ravenclaw, but her choice- whether she realised it or not- to put bravery on a higher pedestal than intelligence shows us that no one is just what the definition of their house is. Pretty much all the main, major, and more interesting minor characters have shown bits and pieces of their personality that betrays their other traits- what makes up their personality. What House we end up in is determined by what we happen to value the most. Obviously, this becomes an important trait in the definition of our character's personality, but it is not the sole defining factor in what type of person we become.
So please- whether you write canon or OC's, keep this in mind and save the rest of us the pain of reading Super!Slytherin.
With all due respect,
A faithful but slightly despairing fanfiction reader.