I find that Colbert isn't funny, his monologues are predictably political all the time. He has too many politicians on as guests. Why his show usually is number one for the late night talkers is beyond me, since his show is not that entertaining.
Jimmy Fallon is down right annoying. His ego is through the roof. He does have some funny bits, but his constant dancing around the stage and playing air guitar like he is some kind of rock star is embarrassing to watch. NBC seems to love him, and showcasing him in other prime time game shows, or specials which all bomb in the ratings. But yet, here he is again, hyping another prime time special or new book. Wish that he would take a page from Johnny Carson and let his guests talk and be the focus. Fallon is always trying to upstage his guests and be the centre of attention.
Kimmel I like sometimes, and other times find he asks stupid inane questions of his guests. He is the most genuine of the hosts, but a lot of the bits on his show are not funny and sometimes kind of crude. He has always had a bit of a fixation regarding Canada and talks about the country and politicians more than the other hosts. Remember his months of talking about the late Rob Ford almost daily in his monologues? Or sending Guillermo and a crew to Dildo Newfoundland to interview the locals about Jimmy running for mayor.
Seth Meyers is my favourite, but some won't like his humour. He is very political, however usually confines it to his very funny A Closer Look. His bits and comments usually make me laugh. Seth does a great impersonation of Trump in terms of the voice and mannerisms. Since his show is on later, the program is a bit more laid back and the host not as charged up as Fallon and Colbert.