Dany's thoughts this time, after she took control. From the attitude of her brother (who creeped me out from the first time I saw him) I like to think that Dany never really got treated as a person and when Drogo sees her raw power he falls completely for her even if the Dothraki have no word for love.
It wasn't her first time by a long shot. No, Drogo had taken her many times, but this time Daenerys didn't feel like a slave. For the first time in... in as long as she could remember, she felt as if a weight had been taken off of her chest it was like she could breathe again. For the first time she felt as though she was important, like she wasn't just a pawn in somebody else's game, she wasn't just a pretty trinket. She wasn't just somebody's daughter or sister or wife, she was Daenerys Stormborn of the house Targaryen and Kahleesi of Khal Drogo's khaleesar.
Curled up in Drogo's arms Daenerys reflected on her feelings. No, it wasn't that she felt powerful, it was that for the first time in her life she felt truly loved.