Margaret Thatcher is being celebrated by conservatives for various economic deeds, some of which were probably useful. She did break the unions and sell off a lot of socialist enterprises, as well as lowering taxes on the rich and raising them on lower income people. They also like her bellicosity, smashing the Argentine invasion of the Falklands and pushing Bush I into the first Gulf War.
I think these miss her real historical importance, which was the role that she played in the end of the Soviet Union. Thatcher was a key player in getting Reagan and Gorbachev talking, with all the consequences that flowed from that.