The following is a debate featuring Roman Catholics Archbishop John Onaiyekan and MP Anne Widdecombe (Conservative) against Stephen Fry and Christopher Hitchens. The debate went well for the Negative according to the poll results released during the debate. Patrick Madrid, who brought this to my attention, agreed with Richard Dawkins in characterizing the debate as "a rout." (link to Madrid) Madrid seems to think that if Peter Kreeft, Benjamin Wiker, Robert George, Dinesh D'Souza, Helen Alvare, Alan Keyes, John Corapi, or Scott Hahn had debated for the Roman Catholic position, the result would have been different.
The result is what it is. I would not tend to base my criticism of Roman Catholicism on the grounds that Hitchens and Fry used.
Link to video - Sorry, but embedding seems to have problems not auto-playing.