That's a tough one. Probably Great Britain or the Netherlands. Both countries had gotten rich with their maritime merchant trading companies, with England having various companies named after wherever they mostly traded, e.g., Hudson's Bay, Muscovy, Levant, East India Companies, etc. and then Netherlands had the Dutch East Indies Company, and this was for the most part, a peaceful period for them, and Netherlands ultimately got it's independence from Spain. However, for Netherlands they were one of the actors during the Thirty Years War, which devastated anybody involved. And then for GB, 1776 was probably a little bit of a down point for them. And then France had all their aristocrats get their heads chopped off during the French Revolution. Before then, they had been having various rows with England, but were probably okay until later on in the 1700's.
But the rest of Europe, especially the Hapsburg states, and the Holy Roman Empire, and particularly, "Prussia" modern-day, "Germany" was really hit hard by the Thirty Years War. More people in Europe died during this conflict than any other conflict until WW1. And Germany, and other Holy Roman Empire countries were poverty-stricken from the beginning of the 1700's on for a long time, so yea, I'd have to go with Great Britain or Netherlands because they got a lot of territories in their maritime endeavors and new trading partners. In fact, Benjamin Franklin was dispatched to the Netherlands to court them for post-independence loans to help us recover, and for forging trade. Prior to that, he had been courting France, and then they started to have civil unrest, leading up to their own revolution.