Royal Purple is probably top2-3 as far as Synthetics go. As far as conventional oils, Valvoline Durablend is one of the best and cheap too.
I used to use Mobil1 until I saw a big test on all the major oil brands and Mobil1 oils did horrible.
I'll be running Royal Purple 10-30 Synthetic in the motor and Redline Shockproof in the tranny. At $7-9 a quart for the fluids named above though, it's expensive as hell!......but well worth it, IMO.
- JCC