Thacher's wariness of government overreach influenced her views on the European Union, of which she was deeply skeptical. Andrew Sullivan of the Dish credits Thatcher with Britain's avoidance of adopting the euro:
Perhaps in future years, her legacy might be better seen as a last, sane defense of the nation-state as the least worst political unit in human civilization. Her deep suspicion of the European project was rooted in memories of the Blitz, but it was also prescient and wise. Without her, it is doubtful the British would have kept their currency and their independence. They would have German financiers going over the budget in Whitehall by now, as they are in Greece and Portugal and Cyprus. She did not therefore only resuscitate economic freedom in Britain, she kept Britain itself free as an independent nation. Neither achievement was inevitable; in fact, each was a function of a single woman's will-power. To have achieved both makes her easily the greatest 20th century prime minister after Churchill.
As noted above, reactions to Thatcher's death are as varied and contentious as her policies were during her time as prime minister. Kevin Drum of Mother Jones says this is typical of a controversial public figure:
When a polarizing figure dies, why shouldn't the reaction be polarized too? The British, bless their hearts, have a tradition of being a bit more bluntly truthful in their obituaries than us Americans, and I'm all for it. Margaret Thatcher led a very public, very contentious life, and was never one to clutch her pearls when she was attacked. If she could take the abuse while she lived, I think her supporters can take it after she's died. This doesn't mean that literally anything goes – George Galloway's "Tramp the dirt down" is typically over the top—but it does mean that if yesterday you thought her legacy was a terrible one, there's no good reason not to say so today. And no reason to be too scrupulously polite about it, either.
Corrected 04/08/2013: A previous version of this blog post stated that Margaret Thatcher was Britain’s longest serving prime minister. Thatcher was the longest serving prime minister of the 20th century, not the country’s entire history.