Your safest bet is to get something edible like chocolates or cookies of a foreign brand (e.g. Lindt chocolates, Danish Cookies). It is all about "giving your friend face", "equal value rendered" (how much they need to spend to entertain you, for example, by giving you lunch and dinner), "consumer expectations" (watch the ads on TV to gauge what the prevailing expectations are), "your own perceived identity and financial ability". These above are the key considerations.
It also depends on the socio-economic profile of your hosts. If they are immensely rich (meaning they have everything and travel a lot to all the top international cities), then there is no point giving them anything other than a beautiful orchid plant for the entire family.
In any event, work within your budget. There is no need to break your back to please.