Crisps that taste like the flavour on the packet:
Salt and Vinegar
Salt and Black Pepper
Crisps that taste about as far away from the flavour on the packet as it's possible to go without involving NASA:
Beef 'n' Onion
Cheese 'n' Onion
All the others.
If I were Walkers et al, I'd just have another look in my special kitchen cupboard, and pick another condiment/preserve. I'm not sure what's left in there - perhaps soy sauce or strawberry jam? Cheeky swines.