Where can i find the least expensive airfare in europe that accepts american credit cards?

This site identifies all the budget airlines with links to their websites for specific prices and schedules. You can find whether a given airline will accept your card on its website. Most should accept the major cards. As long as you don't have something like Discover that is less widely accepted, you shouldn't have a problem. a href="http://www.whichbudget.com/" rel="nofollow"http://www.whichbudget.com//a