Jimmy Fallon 's first night as host of `` Tonight '' was well-received . The show opened with a monologue by the show's host, who said he had been asked to take over for David Letterman's final episode on CBS in September, and that his decision would be announced Some of the episode 's best moments included Will Smith and U2 .
Jimmy Fallon 's first night as host of `` Tonight '' was well-received . Critics have called him `` easy to like '' and `` fresh '' Online , social media were filled with praise . Some of the episode 's best moments included Will Smith and U2 .