Definitely East Europe or if you want to go mainstream: Berlin. You can also live cheaply in South Europe but the intellectual atmosphere is not the same. This

Definitely East Europe or if you want to go mainstream: Berlin. You can also live cheaply in South Europe but the intellectual atmosphere is not the same. This area is good for summer hollydays. The only problem, in both areas, might be the language. English is enough to survive but maybe not enough to thrive.