The Buran program was discontinued for the lack of funds. That said, the Russian Federal Space Agency (Roscosmos) remains the number one space agency in the world right now, although they receives only around 1/20th of the government funds which the National Aeronautics and Space Administration (NASA) receive. Right now, even the Americans are dependent on the Russians, to transport their astronauts to space.
Buran was stopped because of failures of the N1 Energia rocket tests. Overall, the Russian space program does much, much less than the US program. To understand this all you have to do is line up all the rocket launches of the two countries and the purposes of the launch. This is all public data, although sometimes a launch will simply say "classified payload."
The US program has a totally amazing series of successes with the robotic exploration of Mars, Titan, and now Ceres and Pluto. The polar orbiting Lunar LCROSS and LROC missions mapped the entire Moon down to 1/2 to 1 meter per pixel.
This is all crazy futuristic stuff the public is barely aware of, although Mars does get through to them.
No major country on Earth, including all of those which do space work, would agree that Russia has "the number one space agency."