My favorite would be KB Homes, I had a client monitoring every stage of the construction and bringing outside specialists for the third party opinion and heard only positive reviews. Their energy saving technologies are great. I have not heard any of my clients giving me negative feed back about KB.
DR Horton is one of the best builders in Nevada, I placed a lot of happy buyers into their homes. My fist question at any new home site is if they allow the buyer's to bring an inspector during the construction period. Only solid builders with good quality construction would allow you to do so and would put it in writing. If the builder doesn't allow my client to inspect the house in all and any construction phases, then we walk away.