Almost everything we have that takes those little button cells, I consider disposable.

I'm almost completely on AAs too except for some flashlights and a few 9v users. I still use AAA for some things, like keychain lights, headlamps, alarm clocks, etc. They're still much better than button cells but I try to stick to AA whenever I can.

In hurricane panic buys, I'd say D and AA disappear first. It seems like every family buys a D cell Maglite and batteries for a month. AAA and 9v aren't as popular, but nobody buys C cells.

I've definitely had the experience of seeing just C cells on the shelf. I was a big user of C cells in a Pelican SabreLite, but now I mostly use LED lights powered by rechargable AA cells. From an old Backpacker magazine article, I remember them saying that C cells are the most power for weight (in an alkaline).