Lala is the most generic.
WHUH OH LOOK OUT GUYS A SPUNKY GIRL WITH LARGE BREASTS PINK HAIR AND A LOVE OF BEING NAKED IS HERE GODDAMN HOW ORIGINAL
OH WAIT SHE'S AN ALIEN TOO EVEN BETTER
Haruna's supposed to be a normal girl, and the author pulls that off well. Her normalcy among the other wacky characters + the whole relationship between her and Rito make her the most adorable and desirable.