I don't own a Nikon but from what I understand, the new Nikon 18-200 is considered a good lens for this range (albeit quite pricy).
You can find a a comprehensive review here
You will probably get better results if you already own high quality set of 18-70, 70-300 but if you are looking to carry only one lens and don’t mind spending the ~800$ for the Nikon, it may be right for you.