Conan Christopher O'Brien (born April 18, 1963) is an American television host, comedian, writer, producer and performer. Since November 2010 he has hosted Conan, a late-night talk show that airs on the American cable television station TBS.

O'Brien was born in Brookline, Massachusetts, and raised in an Irish Catholic family. He served as president of the Harvard Lampoon while attending Harvard University, and was a writer for the sketch comedy series Not Necessarily the News. After writing for several comedy shows in Los Angeles, he joined the writing staff of Saturday Night Live, and later of The Simpsons. He hosted Late Night with Conan O'Brien from 1993 to 2009, followed by seven months hosting The Tonight Show with Conan O'Brien, the only person to serve as the permanent host for both NBC programs.

O'Brien was born in Brookline, Massachusetts (a suburb of Boston) to Thomas O'Brien, a physician, epidemiologist, and professor of medicine at Harvard, and Ruth O'Brien (née Reardon), an attorney and partner at the Boston firm Ropes & Gray. He is the third of six children. O'Brien's family is Irish Catholic and descends from pre-Civil War era immigrants. In a Late Night episode, O'Brien paid a visit to County Kerry, Ireland, where his ancestors originated.

David Michael Letterman (born April 12, 1947) is an American television host and comedian. He hosts the late night television talk show, Late Show with David Letterman, broadcast on CBS. Letterman has been a fixture on late night television since the 1982 debut of Late Night with David Letterman on NBC. Letterman recently surpassed friend and mentor Johnny Carson for having the longest late-night hosting career in the United States of America.

Letterman is also a television and film producer. His company Worldwide Pants produces his show as well as its network follow-up The Late Late Show with Craig Ferguson. Worldwide Pants has also produced several prime-time comedies, the most successful of which was Everybody Loves Raymond, currently in syndication.

In 1996, David Letterman was ranked #45 on TV Guide's 50 Greatest TV Stars of All Time.

Letterman was born in Indianapolis, Indiana. His father, Harry Joseph Letterman (April 1915 – February 1973), was a florist of British descent; his mother Dorothy Letterman (née Hofert, now Dorothy Mengering), a Presbyterian church secretary of German descent, is an occasional figure on the show, usually at holidays and birthdays.

John William "Will" Ferrell (/ˈfɛrəl/; born July 16, 1967) is an American comedian, impressionist, actor, and writer. Ferrell first established himself in the mid 1990s as a cast member on the NBC sketch comedy show Saturday Night Live, and has subsequently starred in the comedy films Old School, Elf, Anchorman, Talladega Nights, Stranger than Fiction, Blades of Glory, Semi-Pro, and The Other Guys. He is considered a member of the "Frat Pack", a generation of leading Hollywood comic actors who emerged in the late 1990s and the 2000s, including Jack Black, Ben Stiller, Steve Carell, Vince Vaughn, and brothers Owen and Luke Wilson.

Ferrell was born in Irvine, California, the son of Betty Kay (née Overman), a teacher who taught at Old Mill School elementary school and Santa Ana College, and Roy Lee Ferrell, Jr., a musician with The Righteous Brothers. His parents were both natives of Roanoke Rapids, North Carolina, and moved to California in 1964; Ferrell has Irish ancestry. Ferrell has a younger brother, Patrick. When he was 8, his parents divorced. Ferrell said of the divorce, "I was the type of kid who would say, 'Hey Look at the bright side! We'll have two Christmases.'" The divorce was amicable and both parents were committed to their children. The biggest problem was Lee's line of work. As a person in show business, his paychecks were never steady and he was gone from home months at a time. Growing up in the environment made Ferrell not want to go into show business, but get a steady job.