Good Lonely Planet article on countries that can still be traveled on the cheap.
Lonley Planet's list includes:
It's a good list, but we would repectfully add Croatia and Thailand to name a few. Where would you add to the list?
There are literally thousands of Croatia vacation rentals near the beach on the coast or Islands for under $50 / 40 € per night.
There are amazing Thailand villas near the beach which can also be found for under $50.