Luna and Hermione
They couldn't really be more different they already were, Luna reflected.
She was drifty and dreamy. Hermione was sensible.
She enjoyed playing with her heart on her sleeve. Hermione kept her emotions carefully concealed, always.
She was silly and didn't care. Hermione was smarter than her, easily, and she was harder working, more amusing, a better friend, and cared adequately about everything.
They both had their flaws and their weaknesses – neither was better than the other, but they were very different. But one joint thing about them was that they were best friends. Luna and Hermione were best friends, and they always would be, and that would always be enough.
This is dedicated to my lovely friend who knows who she is, because although in completely different ways, we are also utterly different, and yet we manage to get along almost all the time xD