I was shopping for a cheap and easy flight to Las Vegas in spring time and found this (booked too):

 

Saigon SGN - Japan NRT - San Francisco SFO - Las Vegas LAS. 21 hours total, Price $ 637 one way.

By Japan Airlines which has very good service and planes.

 

Via Seattle SEA had been a little faster and better but the price was $ 400 more.

 

I looked other destinations too and Saigon SGN was always cheaper, sometimes much cheaper than others. Maybe less airport taxes?

 

 

The more stops, the cheaper the flight.

I prefer the least amount of stops to get from point A to point B.....

I agree. IF you can sit and suffer non-stop.

I can't. 7h is max but now one leg is 9h.

 

Check those stopovers carefully, I almost book one where it had a 27 hour layover.

They are 2h40min in Tokio and 6h 22min in SFO. I don't mind at all. My legs need them badly too.

 

The stopover in SF seems excessive (over 6 hours). There must be multiple flights per hour SF to LV.

Yah. Fly Xiamen BKK-LAX, save 200, take cheap Spirit flight to LAS, +41.