Depends, Lars.
Powerstroke:
Winter (Oct-Apr) I run Valvoline 5/40 synthetic.
Summer (Rest of the year) I run Valvoline 15/40 Dinosaur Flesh.
Two cars: 91 Cutlass Calais/92 Subaru Loyale
Year round Napa (Valvoline) 5/30 Dino with top-offs between oil changes of whatever I can find around the shop for the oil-burning Subaru. It goes through a quart every 500 miles or so.
Motorcycle:
Valvoline 10/40 bike stuff....Dinosaur.
I'll vote for Dino oil because I use more of it.