If you have a supplier for it, I recommend AMSOIL. I ran that oil in my truck and all my lawn equipment when I had my own lawn service.
http://www.amsoil.com/storefront/amo.aspx
This stuff is incredible. I used to work in the auto repair industry and changed oil with other synthetics and nothing compares to it. When I change to AMSOIL in my truck, the engine already had 120,000 miles on it. The engine smoothed out so well that it did not vibrate and completely changed tone. I checked the oil after 3000 miles and it was slightly low, but the color hadn't changed from when it was poured out of the bottle. I have since replaced that truck but still have it in the lawn equipment.
But I also have to agree that Mobil 1 is great as well.