Colbert's show is centered on politics.
Most of his segments involve the discussion of the current presidential election. He offers a humorous spin to the kind of political news you would find on networks such as CNN.
He also relates better to the geek crowd than the other late night hosts. Neil Tyson is a regular guest on the show, for example. Some segments have involved debates about fictional characters. His show is tailored for a young, educated audience. Kimmel, on the other hand, has mocked the Let's Play concept and been disrespectful with regards to numerous issues, while Conan is not particularly knowledgeable about topics that millennials relate to. O'Brien's show is no longer as amusing as it once was either. His guests now carry the show's humor, while the remotes are few and far between. Fallon's show revolves around game segments, he isn't very funny, and he also comes across as not being very genuine as a person; this has resulted in some backlash to his show from younger audiences. James Corden and Seth Myers' shows, meanwhile, are boring -- neither of them have any presence or personality.
Craig Ferguson was the best late night host of the past decade. In Canada, Conan airs on CTV, and when Ferguson was on, Conan would air the following hour. It was easy to tune in to a double-header of The Late Late Show and Conan. Since the change in scheduling last year, I have found myself tuning in more frequently to Colbert's show than any of the others'.
It's difficult to stay connected with Conan, as the content on the show's YouTube channel has been geoblocked in Canada.