Question: Which channel in youtube has the most subscribers?
Disambiguated questions and answers: question: What was the Youtube channel with the most subscribers as of December 23, 2013?
What was the Youtube channel with the most subscribers as of December 12, 2013?
What was the Youtube channel with the most subscribers as of December 28, 2013?
answer: PewDiePie
YouTube Spotlight
PewDiePie
Natural Questions answer: PewDiePie (from the Wikipedia article "List of most-subscribed YouTube channels")