The Soviet invasion of Czechoslovakia that ended the 'Prague Spring' happened just 40 years ago. At the time, it was a shocking event. Radio Free Europe has a short then-and-now video that gives a good idea of what it felt like, both for the Czechoslovaks and for the soldiers in the invading army.
Yet by many measures, what Russia is doing in Georgia is worse: see the first-person reporting by journalist Michael Totten at City Journal. The Soviets didn't destroy Czechoslovak cities and murder people indiscriminately; irregular Cossack paramilitaries weren't let loose on the local populace; and no wave of refugees flooded the capital city.