Three Answers Required:The American who succeeded Tom Snyder as the host of a late night CBS show, the Scotsman who succeeded that successor, who hosted a late night CBS show through 2014 and the Englishman who succeeded that succeeding successor in 2014 in hosting a late night CBS show (who, coincidentally, played Craig Owens in "The Lodger" and "Closing Time" episodes of Doctor Who.)
Craig Kilborn, Craig Ferguson, and James Corden