1) Free's "All Right Now". They cut off the bridge where there's just empty space.

2) GNR's "Sweet Child O' Mine". They lop off the second part of the guitar intro and some other stuff later on.

3) The Who's "Who Are You?". The entire third verse, which is the most important part.

Radio airtime is not all THAT valuable. If they can let Drew & Mike (my local morning zoo) or Howard Stern or Bob & Tom or Yip & Yap or whoever spent five hours every day making extended fart jokes and prank calls, they can bloody well play songs in their entirety. I think we should all make it a point to call in as often as possible and request "Stairway to Heaven", "Hey Jude", "Inna-Gadda-Da-Vida", "Alice's Restaurant", "November Rain", "American Pie", and "Maggot Brain" as often as possible. Forearmed!