First oil I can recall being poured into an engine in front of me, Pennzoil 10W-30 (positive on the brand, almost positive on the viscosity).
First oil I used doing an oil change myself, Royal Purple 10W-30. My Dad got a 5 gallon jug of the stuff back in the late 80s from GE Plastics and I was taught how do an oil change on it.
The oil I poured into my first car, Mobil 1 5W-30.