The Canadian Caper

When the American embassy in Tehran was stormed by angry students in 1979, six Americans made it out of the embassy and onto the streets of Tehran without notice. After several months in hiding at the Canadian ambassador's house, a joint US-Canadian operation successfully retrieved them from Iran by pretending to be a film crew on a location shoot. You can watch Ben Affleck's Argo for the entertaining drama-y version, or read Wikipedia for the drier truth-ier version:
The Canadian Caper

Sometimes dramatic license helps to make a good story. Even though the premise of the Canadian Caper has a stranger-than-fiction vibe to it from the start, Affleck downplayed the Canadian role in the operation and accentuated the nearness of failure to streamline and spice the story. Mark Lijek's account on Slate tells the faithful, though less melodramatic story of what really happened. It's still quite exciting, even if it's not quite ready to be Oscar bait.

This is one of those rare spy stories where everyone won. The fugitive six posed no threat to the Iranians, but had they been captured, the revolutionaries would've had to do something awful to them out of suspicion. Far better for them simply to never know the six were there until they were being celebrated back on American soil. It was good for America, good for Canada, good for Iran, and good for Ben Affleck. I'd wager that very few things in history have satisfied those four conditions.