Poland's first partly free election was on 4 June 1989, preceded by the roundtable negotiations.

The protests in Czechoslovakia came later, called the Velvet Revolution, from 17 to 28 November 1989. In June 1990, Czechoslovakia held its first democratic elections, a year after Poland.

Poland paved the way for the whole of central and eastern Europe. The Round Table produced the negotiated-exit template that Hungary built on in its own talks that summer, and that Czechoslovakia, East Germany, and the Baltics drew on as their regimes fell within months.

And it did so from the deepest macroeconomic crisis of any of the satellite states: hyperinflation running into the hundreds of percent by late 1989, an unresolved sovereign default from 1981, and chronic shortages.

Since then Poland has converged fastest of any of them. From a low base it has climbed to the upper-middle of central and eastern Europe by GDP per capita PPP, overtaken Hungary, and is now closing on Czechia and Slovenia.

In chronological sense.

See: https://en.wikipedia.org/wiki/Revolutions_of_1989

Round Table agreement, which paved the way to the partially free elections in 1989 won by the opposition, preceded similar events in other countries by several months including Velvet Revolution in Czechoslovakia and the Fall of Berlin Wall.

The OP shows the per capita GDP growth of the former Soviet bloc states since 1990. Poland is #1 at 252%, Romania #2 at 148%; Czechia is last at 72%.

Ukraine didn't have Russian troops occupying anything but the leased Crimean bases before the war started (and I do count the start of the war as being immediately after Euromaidan)... Yet in 2013, it was the second poorest country in Europe. (Ahead of Moldova, which has been occupied for decades, but significantly behind Belarus and Bulgaria)

Romania?