The largest ones I'm able to get from my local grocery store are the 3 1/2 gallon ones.
But then I'm not able to carry and lift a full 5 gal very often at my age, so it works out ok.
I like to use them for storage also, to keep the bugs and mice out as well as some opossum and raccoons for some stuff, but it's hard to get them to save the lids.
The best luck I have for the 5 gals is painting contractors on a job site and hydraulic fluid for my tractor.
I got stuck in town without one a couple of years ago, had to buy one.
Wow, I paid more for the lid than I did for lid & bucket years ago, ridiculous.