I lived in São Paulo, Brasil for 2 years, back in my single days (taught at a missionary school) and I brought with me taco seasoning packets. That's one thing I really missed and we couldn't get. Also, canned pumpkin for Thanksgiving pies. Once, a friend of mine went back to the States to visit and when she got on the plane in Dallas, the last thing she did was buy a Taco Bell burrito for me. She kept it in her pocket the whole flight. I had teased her before she left about bringing Taco Bell back for me, and she did. That was the only fast food I really missed. McDonalds was all over São Paulo and we could get American pizza at the occasional Pizza Hut, but Mexican food was not available.
I brought back to the States cans of Guarana, which is one of the most popular soft drinks in Brasil. I also brought back chocolates and pao de queijo (Brazilian cheese bread) mix.