The Tax Foundation, one of the nation’s leading independent tax policy research organizations, has released its 2014 report on international tax competitiveness:

The Tax Foundation’s International Tax Competitiveness Index (ITCI) measures the degree to which the 34 OECD countries’ tax systems promote competitiveness through low tax burdens on business investment and neutrality through a well-structured tax code. The ITCI considers more than forty variables across five categories: Corporate Taxes, Consumption Taxes, Property Taxes, Individual Taxes, and International Tax Rules. The ITCI attempts to display not only which countries provide the best tax environment for investment but also the best tax environment to start and grow a business.

Out of the 34 members of the Organisation for Economic Co-operation and Development (OECD), representing many of the world's top economies, the U.S. ranked 32.

For further analysis, see Paul Caron's post on TaxProf Blog.  The Hill is somewhat blunter in its piece "Study: US tax code among world's worst," to which (among other reports) Professor Caron links.