After Conan quit "The Tonight Show" in 2010, it essentially closed the door on him returning. NBC spent a lot of money building his studio on the Universal lot. Shortly after, NBC Universal was sold to Comcast, who made lots of budget cuts. read more
O'Brien might have taken over "The Late Show" a decade ago, if Letterman decided to leave then. However, that did not happen and he agreed in 2005 to replace Jay Leno in 2009. We might never publically know if he was in the running for "The Late Show" when Letterman announced his retirement in April 2014. read more
In 2009, NBC handed the show to Conan O'Brien, only to reverse itself and bring Leno back the following year. O'Brien quit the network for TBS and Leno came to be seen, for the second time, as a world-class spoiler of others' careers. read more
The only late night host that remained neutral was Jimmy Fallon, who refused to take sides, calling O'Brien and Leno "two of my heroes and two of my friends". He later joked that, "There's been three hosts of Late Night: David Letterman, Conan O'Brien, and me. read more