David Letterman has been credited as a comedy pioneer by many, including his talk show competition. On the night before he would host his final Late Show show, Jimmy Fallon and Jimmy Kimmel both shared how they were influenced by David Letterman.
Kristen Wiig stopped by 'The Tonight Show Starring Jimmy Fallon' and did an entire interview in the character of Daenerys Targaryen from 'Game of Thrones'!
Ariana Grande has one set of pipes, but the "One Last Time singer shows just how well she uses them when she impersonated Celine Dion on The Tonight Show Starring Jimmy Fallon last night (March 20).