In general, a lot of us on here use Royal Purple or Amsoil. Dont ask an Amsoil dealer what they think, because relating oil to a religion, they are the fanatical muslim terrorists of the group. Hell, they will even make up crap about other oil.. even citing bs on Amsoil's site at times. Great oil, the most over the top fanatical dealers I have ever met. I personally use RP in my cars.
But honestly, from my experience and seeing what my dad has seen at his shop for years and years and years, most decent oils (whether dino or synthetic) have proven just fine for very long engine lifes as long as the oil is changed like it should be, checked and kept full regularly and the rest of the car is maintained well.
I will say though, out of the potential (I say potential because it is hard to tell for sure sometimes due to the types of failures) oil issues I know of, more of them are from Penzoil (when talking about the major brands). But again, that is not solid data or proof.. just loose correlation.
I use synthetics, and by that I mean group IV or V, which out of the common brands I believe leaves it to RP and Amsoil these days. Even Mobile 1 (which is decent oil, but made of group III base stock) is only able to say they are full synth due to some very loose interpretations of the term.
Curious to see how G Oil turns out. I know that some race teams use it and that you can buy it in standard weights for street vehicles. Interested to see how it performs long term. They supposedly even have something you can mix it with when you dispose of it that effectively turns it into "soil" ... fully biodegradable. Interesting at least. Their race team just won the Long Beach Grand Prix this year too