A good one I heard recently, a friend of mine was doing his first solo circuit flight...
"ABC is lefthand downwind 23L touch and go"
Tower - "ABC, continue approach for 23R, you're number 3 behind a C172 late downwind and a Beech1900 on 3 mile final for the left"
"Cleared to land 23R ABC"
"No, you are not cleared to land, you are cleared to continue for the right, number 3, report sighting of a cessna and a beech about to land on the left"
"copy traffic, cleared for 23L, ABC"
"No!! you're now number 2 behind a cessna also for the right, thats 23R!!!"
"copy number 3"
give up!