Oh, so many - you can pick and choose what you like if you've already seen tho. :D Not sure how "silly" the girl has to be, but hope this helps!
-Bull Fighting (basketball related, she's spoiled but well-intentioned)
-Down With Love (She's happy-go-lucky not interested in love)
-Faith (She's modern lady trapped in yesteryears and their thinking - puts up a fuss)
-Full House (she's eccentric, socially odd)
-Goong (every day girl trying to conform into princess mold and lifestyle changes)
-Green Rose (not silly princess but happy-go-lucky despite harships)
-Hana Kimi (gender bender and antics that come with it)
-My Girl (she's silly, borderline con-artist for survival)
-I Really Really Like You (more of a hick/silly like she doesn't know city life)
-ISWAK/Playful Kiss (Same plot TW/K - She's silly, almost naive and boycrazy)
-Lie to Me (Not silly perse, but does silly, funny, impulsive things)
-Long Vacation (she's nonchalante, spontaneous character)
-Miss No Good (She's silly to the point of annoying)
-My Princess (Ordinary girl trying to fit into princess role)
-Nodame Cantabile (She's silly/eccentric)
-Prince Turns to Frog (Happy-go-lucky country girl)
-Romantic Princess (ordinary girl fitting into high society)
-Stars Falling From the Sky (She's spoiled, self-centered to begin with, then life changes)
-You're Beautiful (Gender Bender and all that entails)
-Sweet Relationship (She started rich/spoiled, becomes poor - not so silly)
-The Vineyard Man (She's city girl stuck in the country)
-Wild Romance (She's act before you think, then live with consequences)
