Good times in Thailand, both in Bangkok along Kho San Road for westerners, and on the islands like kho sum moi. Many westerners spend lengthy periods of time on the islands during the winter, thanks to extremely cheap but decent huts right on the beach, along with good nightlife nearby including raves along the beaches. You would have the benefit of great drugs as well; and can hire an escort for a week for next to nothing.
The advantage with Asia is that you can travel amongst many cultures and different countries cheaply. Try going to Myanmar, both because it's relatively untouched/unwesternized and also charming. Cambodia and Vietnam would also be interesting; you'd have to read up on them.
Brazil i've never been. To compare you should do some reading at one of the bookstores, and find sites comparable to getbig, for travel.