Jimmy Kimmel is one of the most popular TV show hosts in the USA.
He hosts (and is an executive producer of) ‘Jimmy Kimmel Live’, which started airing in 2003.

(Courtesy: ABC.com)
Jimmy Kimmel Live is like any typical chat show, which includes interviews with celebrities and political personalities.

(Courtesy: Variety.com)

(Courtesy: Fortune.com)
While Jimmy Kimmel might not necessarily the best TV show host, he is certainly among the top names owing to the massive reach ABC Network– which homes his show – brings him. (Much like what NBC does for Jimmy Fallon!)
NOTE: Don’t confuse between Jimmy Kimmel and Jimmy Fallon. They are two different individuals who have their own separate chat shows on different networks. Both are extremely popular and both flex massive influence in pop culture.

(Courtesy: CNN)
Earlier this year, Jimmy Kimmel also became the new host of American ‘Who Wants to Be a Millionaire’, a show that originally hit the TV for the first time in 1999. The first season of the show starring Jimmy Kimmel traded fairly in the ratings. The host asked questions to some renowned personalities like Anderson Cooper and Eric Stonestreet. Per reports, the shooting for the second season of ‘Who Wants to Be a Millionaire’ has started now.

(Courtesy: Dailymail.co.uk)

(Courtesy: ABCnews.com)
I hope this addresses your question.

