Мне больше нравится без молока. - I like it better without milk.
без сахара - without sugar
Я хотел с сахаром, но без молока. - I wanted it with sugar but without milk.
Я там буду до субботы. - I'll be there until Saturday.
вы не хотите чашку кофе?
- Don't you want a cup of coffee?
- Would you like a cup of coffee?
When in Russian we ask "не хотите ли вы ..." we don't ask this question to clarify that the person really don't want something. It is just a sort of polite form to offer something.
So "хотите чашку кофе" and "не хотите чашку кофе" are equal.