Books! Books are not clutter if your girls read them.
Art materials (drawing, painting, etc., as distinguished from crafts) are not clutter, either, and they can open a new field of imagination - even if it's just a box of colored pencils and a pad of drawing paper.
What about hair things? Comb and brush sets with their names on them? A whole big box full of barrettes and headbands and scruchies and whatever else they like? (Correction: get small boxes, not big ones. This stuff adds up!)
Is there something special they'd like to do with Mom or Dad? What about a tiny gift-wrapped box with a promise inside that "You and I will go camping together next summer" or some such thing?
There are all sorts of board games and family card games in the stores this time of year - so many that you'll need to ask your daughters' friends parents for recommendations.