Presbyterian pastor Dr. Mark D. Roberts debated noted atheist Christopher Hitchens on a radio program half-way through last year. Here's the audio:
part 1
part 2
part 3
Read the debate transcript here
part 1
part 2
part 3
Read the debate transcript here
Roberts did terribly, it was nearly a total disgrace.
Hitchens is no mastermind, and the fact that Roberts couldn't handle him shows that Roberts should stick to pastor-ing, not debating blasphemers like Hitchens.