Here's a (non-exhaustive) list of what the Chinese government has said about the June 4th crackdown. Over time, the government's tone has morphed into something a bit less strident. In the early '90s, the PRC called it "counter-revolutionary turmoil" or just "turmoil" for short. Then it modified that to "the Tiananmen incident." In a 2003 interview with the Post, Premier Wen Jiabao gave what I thought to be the most illuminating answer, framing the "incident" as something that occurred "in the last century" with the clear implication that it was irrelevant to today's China.

Compiled by Nicholas Bequelin:

June 1989
Zhang Gong, spokesman of the army
Nobody was killed in the Tiananmen Square, and there was nobody crushed by tanks in the Square.

June 6, 1989
Yuan Mu, spokesperson of the State Council
During the "clearing" of Tiananmen Square, 5,000 soldiers were injured, and 2,000 civilians and "rebels" were also injured, 300 soldiers and "law-breaking criminals" died, including 23 university students.

June 16, 1989
Yuan Mu(interviewed by the U.S. news station ABC)
The news clips shot by ABC depicting troops entering the Square killing civilians and students were actually created by "advance technology" with the aim of twisting the facts.

1990, Jiang Zemin, General Secretary
Dismissed international condemnation of the Tiananmen Massacre as "much ado about nothing."

January 2001, Foreign Ministry spokesman Zhu Bangzao
Defended the use of deadly force against unarmed civilians in June 1989 as "...timely and resolute measures...extremely necessary for the stability and development of the country."

November 22, 2003 Interview with Premier Wen Jiabao with The Washington Post
"In the last century, at the turn of the 1980s and 1990s, drastic changes took place in the Soviet Union and countries of Eastern Europe. In China, a political disturbance occurred. At that time, the party and government of China adopted resolute measures in a timely fashion to safeguard social stability and became more determined to press ahead with China's reform and opening up. Our development over the past years has proven that stability is of vital importance for China. As premier of this country, I think the most important issue for me is to ensure stability and development. This is because China has 1.3 billion people."

2008 Qin Gang, spokesperson of the Foreign Ministry
Regarding the political incident that took place at the end of the 1980s, there is already a clear conclusion.

2009 Zhao Qizheng, spokeperson of the Chinese People's Consultative Conference
The government has already reached the verdict on "June Fourth", and the stability of the country was the foremost priority.