The best!

That could. apply to just about any subject nowadays!

   It's pretty simple and straightforward in 2024 IMO.
   Now that motorcycle specific oils and car/light truck oil have gone down defined specific paths for 10+ years now.  In light of API [American Petroleum Institute] becoming somewhat 'vague' regarding motorcycle specific needs, with their kind of 'we think it's good' API spec SG [wet clutch, shared gearbox/engine], thankfully oil companies wishing to test/confirm/advertise their oil to specific needs today have JASO [Japanese Automotive Specification Organization].

  JASO MA and JASO MA2 are motorcycle oil test industry standard today. I won't run oil in any of my bikes without this test certification. Even on machines I have where clutch-gearbox-engine are separate lubrication entities.

   The one age old requirement that someone might actually at least think about, is machine viscosity requirements. While we here north of the 49th parallel live in a coolish temperate country, we do 80% of our riding in the warmest 4 months of the season where it can get +40C in BC. If you've got a liquid cooled modern machine, not such an issue, but if you are on an air cooled machine known for hot running, and smallish capacity, viscosity requirement really should be strongly studied, perhaps adhered to.
  One of my machines has what I will deem a high requirement oil machine. The XR650L runs hot, has loose clearances because its got a big piston, small oil capacity, and shared oil requirements. I could easily run inexpensive Shell Rotella series [T4, T5, T6, all JASO MA or MA2 rated] but alas they do not have viscosity thicker than 15W-40, too thin for the big red pig. The highest quality 20W-50 for the pig.

Steve, you must be a man, you already have the answer.

  I identify as a man. I do not have purple hair, or a nose ring.

  Normally, I do not enter into conversation unless I am correct. If I do know im incorrect, I’m  grinning and giggling.

If only the people who designed and built the machine could supply some sort of booklet that would describe what oil they recommend using in their machines.

I just run the old through a coffee filter and re-use.

AHAH, that explains why your bike smelled like a TIM HORTONS last time you rode in front of me.

That or the burnt clutch ??