After a long line of party bureaucrats including the almost colorless Leonid Brezhnev, the KGB geriatric Yuri Andropov, Konstantin Chernenko and others that seemed to be almost xerox copies of each other, Gorbachev was a breath of fresh air for people on both sides of the Iron Curtain.
He had a personality. He was pleasant, even charming at times. He smiled and gave interviews to foreign journalists, on one occasion even leaving his limousine motorcade on a whim while in New York City just to shake hands with Americans on the sidewalk. In this way he resembled more an American politician than a Russian dictator.
He also approached communism differently. While he believed in the system still, he thought it should be "adjusted" to fit the more modern economic realities of the 1980s. He instituted a program called perestroika which meant "restructuring". He allowed limited private businesses and private property as an experiment to harness Soviet ingenuity and creativity. He then announced the new policy of Glasnost, or openness. He allowed newspaper reporters more freedom to write what they wanted, even to criticize the government a bit. He put an end to shadowy KGB arrests for simply speaking an opinion in public. And he engaged the West and Ronald Reagan, negotiating over nuclear weapons. His most decisive moment came when he decided not to send the Red Army in to crush revolts in Eastern Europe, letting the Warsaw Pact countries go their own way.
Today, he is more popular in America than he is in Russia.