Jimmy Fallon's first

HitFixJimmy Fallon's first-week guest list: Justin Timberlake, Will Smith, Lady Gaga ...HitFixJimmy Fallon's first-week guest list: Justin Timberlake, Will Smith, Lady Gaga and more. U2, Jerry Seinfeld, Kristen Wiig also set for 'Tonight Show' welcome party. By AP Staff Monday, Feb 10, 2014 8:21 PM. Comments: 2. <p>Lady Gaga</p>. Lady Gaga.