There's many things that make Luna Lovegood odd and different, they make her who she is and George Weasley has a list of his favorite 5 things about Loony Lovegood.
One
She believes in many things, impossible creatures, rare and odd like her.
He often finds her out by the lake searching for strange underwater creatures, or out in the Forbidden Forest feeding a Thestral or two.
There seem to be Nargles hiding around in different objects, according to Luna. Even George has become paranoid of the silly creatures.
A Luna Lovegood who doesn't believe in magical and odd creatures is a true Loony.
Two
Luna Lovegood isn't one to care for her appearance or the newest fashion trends, though her radish earrings are always in style for all she cares.
When he first spotted the wide-eyed girl who spoke of Crumple-Horned Snorkack's he didn't find it the least bit odd that she would own a pair of radish earrings, in fact, he would have found it odd if she didn't own something of the like.
Three
She actually listens to every word he says, though most of the time she seems off in her own world she does pay attention to what George has to say.
If George has to vent about something, he goes to Luna. Whatever it is he has to get off his chest he goes to the only person he knows will actually listen to his ramblings and Luna always listens to every word.
Sometimes she stares off or begins mumbling to herself whilst George rambles on but she always gives a comment when needed and laughs at the right moment.
Not even Fred would listen to his brother go on about all the nonsense he may have to say but Luna is always there to listen, even when he has nothing to say.
Four
She doesn't care for the mean things others have to say, though George always threatens to prank anyone to extreme pain if they dare make fun of her.
She has been made fun of and called names most of her life, all for being who she is.
George admits it, when he first saw Luna he thought she was a little odd but he never once called her something mean or made fun of her. He never even pranked her, not in a bad way anyway.
He makes sure no one calls her names or makes fun of her, though he's an exception and calls her 'Loony' lovingly.
Five
She doesn't know she's beautiful, as radiant as the sun in George's eyes.
Whenever he gets the chance to, which is often, George makes sure to remind Luna of how beautiful she is so that she doesn't forget it.
Most girls would probably make a big show of any boy calling them Beautiful, especially if that boy was one of the Weasley twins, but not Luna. When George does this she smiles softly and looks at him with bright eyes, "Thank you George, you're very beautiful yourself."