Freelance writing credits include this piece about how TV documentaries are funded for The Guardian and this comment piece also for The Guardian.
Sample work for Broadcast magazine is here and here.
Here is an interview with Hugh Fearnley-Whittingstall, which I did for Broadcast magazine.
Here is something on so-called credit crunch programming, with coverage of how the Daily Telegraph ripped it off. They say imitation is the sincerest form of flattery.
You could also look up a couple of other pieces from yonks ago which I enjoyed doing: an interview with CNN founder Ted Turner for The Observer and an interview with US chat show host Jay Leno for The Independent.