Here is an answer based on past experience of 14 years in the trade, it is by no means a generalization:

India: they will always say the can do it, you end up closing the deal with a sales person only to be relayed to someone who is not very fluent in English. You end up micro managing paying a lesser hour but wasting more time. (we stay away from)

Ukraine/Estonia: really good overall, language is a barrier but their math skills really show off in any of their projects. Prices are very competitive

Argentina: Great design and coding skills, If you know spanish then its a breeze. Argentinas pesos situation against the dollar makes it very competitive

Colombia: As well as Argentina very good on the design level, coding skills lets say they are evolving but future looks promising.