I did some research on motor oil some years ago. I looked at all the data I could find on wear rates in various tests, how they handle contaminants, etc. In a nutshell, any synthetic is better than any non-synthetic. Amsoil is the best, but it's also very expensive. At the time I did my research Mobil 1 was a close second, but they've since changed from the more expensive and better base stock to the less expensive type, so I expect they've lost that status.
Bottom line, I use whatever full synthetic is cheap. Mostly that means Walmart's Super Tech, Harvest King from the farm store, or NAPA or Mobil 1 when they're on sale.