No military aircraft – past or present – can beat the altitude and airspeed performance of the SR-71 Blackbird.
It's design and performance evolved out of necessity: "We had a need to know what was going on in other countries," Jeff Duford, a historian at the National Museum of the US Air Force, said. "And the way that we were going to do that was having a photographic aircraft that could fly very high and very fast. And much faster than the U2, which proceeded it. The SR-71 was that answer for the US Air Force and for the United States."
Here's the remarkable story of the SR-71 in a 3 minute mini-doc: