Switzerland was ranked the best country for a comfortable retirement by U.S. News & World Report.LeeYiuTung / iStockSwitzerland tops U.S. News & World Report's best countries for retirement.The rankings consider affordability, healthcare, and quality of life among 89 countries.New Zealand, Portugal, and Australia also ranked high for a comfortable retirement.Many Americans are flocking to Switzerland for their retirement — and for good reasons.Switzerland once again topped this year's U.S.