Colatura di Alici is fish sauce made from anchovies in the same Roman town since the Roman republic. It was used by everyone on everything and also traveled with soldiers across Europe during the empire. It's nice - it tastes "softer" than the Asian fish sauces.

I also buy from Italians at a farmers market here in Switzerland rotten anchovies packed in salt and ground peppercorns. Stinks but when you add one to pasta sauce you're making the smell disappears and tons of glutamates are added.