I loved the way Dany threatened Viserys after he attacked her. I might be misremembering, but she didn't do that in the book, did she? I really should know this since I've already read it 3 times, but oh well.
straight from the books - From AGOT
His fingers dug into her arm painfully and for an instant Dany felt like a child again, quailing in the face of his rage. She reached out with her other hand and grabbed the first thing she touched, the belt she’d hoped to give him, a heavy chain of ornate bronze medallions. She swung it with all her strength.
It caught him full in the face. Viserys let go of her. Blood ran down his cheek where the edge of one of the medallions had sliced it open. “You are the one who forgets himself,” Dany said to him. “Didn’t you learn anything that day in the grass?...