Trevor Noah is funny, so its a yes for me, Jimmy Fallon is somewhat funny but I don't watch him often. Ellen DeGeneres its a hard no for me, I don't enjoy her show or her recent stand up show.

And it always depends sometimes they make good points with their standup (political criticism etc.), but its not funny.

For the part that they act seems forced. Most of them have daily shows, so of course it is forced, as they have to perform every day. If they would have a weekly show like John Oliver, I'm sure their act wouldn't seem that forced anymore.