I have been to Costa Rica twice and I fell in love with Banquete brand Chilero Sauce.
It is a hot sauce with a wonderful flavor but it has some fairly unique properties -- specifically that it is very similar in color and consistency / viscosity to asian sweet and sour sauces. This lets the sauce cling in a thick layer on the food to which it is applied.
I have tried looking for this sauce but it is hard to find even by mail order in the US and the price for shipping from Costa Rica costs many times more than the sauce itself. Apparently a lot of places carry Lizano sauce but this brand of Chilero seems to be left out.