A classic one perhaps... A KLM flight bound for Amsterdam was descending abeam Eelde (EEL) in the Dutch FIR, coming from somewhere up North. Our radar showed the aircraft had initiated a significant turn hence the radar controller investigated...
Maastricht: "KLM1234, confirm you are making a right turn?"
KLM1234: "Affirm! Turning back shortly!"
Maastricht: "KLM1234, what is the reason for the turn?"
KLM1234: "Oh uhm, it's a very clear day today, and banking the aircraft allowed me to see my house from up here..."
Maastricht: "Roger... next time please report before turning"
This is when another pilot stepped in and said: "Hey KLM, can you also see the car on the driveway?"