How high does an airplane go in the sky?

Depending on the type of airframe and aircraft would tell you the maximum altitude an aircraft can obtain. Even then, specific aircraft (i.e. jets, propeller powered planes, biplanes) all have different maximum altitudes or ceilings. To answer the question, what aircraft has the most unrestricted ceiling?, that is the SR-71 Black hawk with a ceiling of roughly 80,000 feet.

*NOTE: Because of the high altitude and air pressure, pilots need a special suit and mask that provides them with protection from the upper recesses of the atmosphere