There are some of us who are old enough to remember when crisps were just that, crisps. No flavours, no salt and just one manufacturer, Smith's.
Of course, that bit about 'no salt' isn't really accurate. Smith's crisps came supplied with a little blue bag of salt lurking somewhere deep inside the packet. Or at least they were meant to. Occasionally, you might find that your packet of crisps didn't have that all important little blue bag but it rarely mattered; all you had to do was to swipe one from your friend who probably found that his bag of crisps had two or three portions of salt in it. (I remember my feeling of utter joy when, as a young child, I opened a bag of Smith's crisps that beat all known records by containing no fewer than 5 packets of salt!).
Eventually, of course, someone had the idea of adding flavourings. The reference works all state that cheese & onion was the first flavour but my earliest recollection of eating flavoured crisps was trying a bag from a new manufacturer, Chipmunk, and absolutely loving the flavour. So what was that flavour? Oxo! (They didn't seem to be on the market for long. Bovril flavour, which came later, was nowhere near as good)
This website might be of interest:
http://www.ilovecrisps.com/
Chris