I changed my mind about the existence of God, if that counts. And about the deterministic view of the universe and the consequential implications for free will. 

If you mean political issues only, not really. I live in the UK; pretty much our whole society is in unison about those particular sorts of issues. The largest disparity in our parties is in economic policy, and the social impact of that really amounts to "should we have a moderate amount of welfare, or a larger amount of welfare?" The differences in opinion are really so minor compared to the huge schisms in American politics.

EDIT: Also, how does "Socialism vs. Capitalism" even make sense as a "vs."? I don't understand this. It's an American thing I think. Extreme Socialism and extreme Capitalism are arguably opposing, purely because the absolute extremes of both require absolute power in differing places, but you can very easily be a socialist capitalist state. Many countries are. The absolute extremes are absolutely irrelevant, as they usually are in any issue.