Wasn't me, but supposedly a true story. A GA aircraft was crossing the Schiphol CTR (class C), which is tricky but great fun. However, more or less overhead the field he managed to get himself slightly lost and overloaded, so ATC decided to give him vectors instead, and have some fun with him.
"PH-ABC now turn left XXX degrees"
"PH-ABC descend 300 feet"
"PH-ABC now turn right XXX degrees"
"PH-ABC now look right and wave"
The control tower at Schiphol is a little over 300 feet high so they were level with the tower, about 1 nm distant. And ATC was waving back.
