I list Memory Cards as a separate category, because they are so widely used. For example, I use memory cards in cameras, smartphones, digital audio recorders, computers and even as the best way to mail digital information to people.
Although microSDHC would be the natural choice for use of one card for all of these purposes, the practical fact of the matter is that they are “too small to handle”. SDHC is easier to handle but is not supported by today’s smartphones, which appear to be exclusively microSD-based; handling is not an issue as a USB connector eliminates the need to insert and remove the microSDHC card in a smartphone.
Flash drives were originally much more popular for computers, but memory card readers soon appeared, first as a high-end built-in feature on many computers, then as an external USB device like the Kingston MobileLite series priced as low as $10.
For memory card compatibility, SanDisk and Lexar are the brands of choice, mostly because they were once the only brands that would work reliably in a popular brand of digital audio recorder.