By JODY THOMPSON Quality! James Corden, playing Gavin And Stacey star Smithy, sings along with George Michael to Wham's I'm Your Man in the brilliant Red Nose Day sketch The most star-studded - and arguably funniest - sketch ever on Comic Relief saw Gordon Brown duetting with JLS as the show smashed its 23-year fund-raising total in the early hours of this morning. Starring James Corden as Gavin