Context would be good, but Have you got something better to do sounds better. Example conversation: Person 1: I want to go to the movies Person 2: I don't want to go to the movies. Person 1: Do you have something better to do? Example conversation 2: Person 1: I don't want to be here. [movie theater] Person 2: Do you have something better to do? Don't= Do not In spoken english people usually say don't instead of do not.