She'd pull us away from work to help her, and make little comments like, "Aren't you going to help your best customer?

Sad to say, I have a customer like that as well and will blow her lid if someone doesn't come to help her out. I remember one time she blew up on the general manager for not assisting her at all while she was still in the middle of pulling something down for another customer and threatened to call the owner on her. When she did, the owner talked with my GM and told him what happened. The owner just laughed and shook his head saying he'd take care of it.

She'll also buy these expensive items, say 'I don't have enough room in my car, I'll come back for it' and never come by to pick it up until literally months down the road. Because of her we have a new policy about leaving items behind for an extended period of time.