There are countless worthy options.
My bid won't rest on the usual drinks -Port wine; Vinho verde; Moscatel; vinho da Madeira, etc.
foodstuffs- pastéis de nata; queijadas; ovos moles; etc. -
even the most orthodox pieces of artisanship- i.e. galo de barcelos; traditional jewelry, typical instruments, etc.
I'm proposing something different that what most people wouldn't venture proposing.
I propose: Malandrice das Caldas
Because there's a dire lack of kitsch phallic decoration out there in the world