If you want to compare economies, a good source is the World Development Indicators from the World Bank. Economic definitions differ and data exist in different currencies, but the World Bank makes the relevant reconciliations. For example, their data are in 2005 U.S. dollars (and thus in real, not nominal, terms). These graphs depict two countries currently in the news whose economies have stagnated. The first is Venezuela, which had been much richer than its neighbor Colombia but has had essentially no growth over the sample period. The second is the Ukraine, which suffered a deep recession in the early 1990s, along with other former Soviet bloc countries. The Ukraine never recovered, while its neighbor to the north, Belarus, did. In fact, the Ukraine’s situation is even grimmer: The data show GDP per capita, but do not show that the population in the Ukraine has actually been falling for several years, which means total GDP has been on a sharp decline.
How these graphs were created: For both, you can either start from the World Development Indicators release and narrow down the choices using the tags or simply search for “constant GDP per capita” for the countries of your choice.
Suggested by Christian Zimmermann