I will have to weigh on this discussion with my own personal favorite: SynLube.
This formula is produced by a very small company but that doesn't mean that they just repackage an oil for sale. They have a unique product.
Composed of 3 solid (all in submicronic form) and 5 liquid lubricants, this oil is designed to last 150K miles/3K engine hours or 10 years. It can last this long because the components are almost entirely enert. And neither summer or winter extreme of temperature is a problem. It is appropriate for any gasoline engine (except rotaries) and any diesel, though the service life is 2K hours in this type engine. Dry lubrication conditions are completely eliminated.
This oil costs substantially more at purchase ($32/quart) but per mile is cheaper than most any oil out there. It is about a quarter of the cost of the 3K dino oil regimen, assuming $25 per change.
I have about 4 years of experience with this oil though that experience is divided out over three vehicles so I don't have any impressive personal figures to report yet. The longest in any one vehicle I have used this lubricant was 18K miles in a Ford Focus. Oil consumption during that time was 4.5 ounces. My current ride, a Ford Ranger has about 6K miles and I will be keeping this vehicle a long time.
At the end of the service life, the oil can be returned to the company and they will provide you with a credit towards the purchase of new oil. The old oil will be microfiltered and the additive package rebalanced. It will then be good as new and will have the same warranty.
They make similar products for the transmissions (both manual and automatic), differential, power steering etc. They have a coolant that lasts 300K miles.
When I first read about this oil, I was a bit skeptical as most people are but when I got back some good answers to my questions, I went ahead and tried their products. I have never had a problem.