Which is the best brand you recommended for heating and air condition units?

You will get many answers on this or any forum to this question. Most are good units. More importantly is go with a company that has a good reputation and been in business a while. Ask friends, neighbors etc for recommendations in your area. Personally, for the money I like Goodman

As esquire1 said Goodman works just fine but your real concern needs to be with the equipment install. Some installers can take the best equipment and turn it into a junk job while others can take much cheaper equipment and install it so it runs almost forever. Worksman ship has always been on the top of my list.