The very first gas containers I used were OVERPRICED, Swiss made, double lined metal.
The hardest "find" were plastic drink bottles with wide mouths, but with all the roadside litter, sometimes a keeper would jump into view.
But thanks to some customer experimentation, and spoiled by having saddlebags on my red cruiser and now my blue recumbent, 33 oz. mouthwash bottles have been a winner. I've not noticed any plastic breakdown, no leaks at the twist on lid. (yet)
In picture 2, I found that rectangular plastic packaging (with the two mouthwash bottles) at a store, it held beef jerky. When I cut the top off it, it fits two bottles into the saddlebag with no spillage, including when I pull up at the gas pumps.
There is also an old wide mouth drink bottle I guess I've had over a year, and another acceptable carrier in the saddlebag, a 48 oz. vegetable oil bottle.
Bigger bottles are really handy on medium (2-300 mile) trips, where you can carry more pre-mixed fuel for the 2 cycle engines, (not as important with the 4 stroke.)
Another customer claims plastic liquor bottles work well.
The mouthwash & vegetable plastic seems to be a heavier grade, and the wide mouth/long neck on the mouthwash bottle really aids "no spill" fill-ups on the side of the road.