Conan O’Brien is the best one who wasn’t even mentioned in the OP. However, among the 3 mentioned, I’ll have to go in this best-to-not-best order:
I just don’t find Dave’s humor to be all that funny, at least not most of the time. And Jay isn’t that funny either but he is not as bad as Dave is most of the time.
Well, I of course would have to go with Carson. He had the best overall show, which is why he didn’t have any competition. Several tried, but none could last against him.
The thing that Johnny was great at that the others are still learning (and may never get) is the interview. Johnny had a way of drawing out the good anecdotes and jokes from the guests, with some of his own wit thrown in. The magic of it was that the audience’s attention was always on the guest. All the other guys can’t seem to do an interview without pulling the focus to themselves. Most of my friends who watch the latenigbt shows don’t seem to care who the guests are at all. I think that’s because the guests have been pushed so far into the background.
I’m also a monologue lover. Johnny did that so well. He had a way of making you enjoy the jokes that bombed as much as the ones that got big laughs.
Now, if I had to choose between the current latenight shows, I generally flip back and forth. Letterman is more fun to watch in the unscripted parts, because his personal wit is less predictable. But his monologue is only four jokes long most nights. So, I like Jay’s monologue better, even though it has a fairly high percentage of lousy jokes.
Later in the shows, I actually pick which show to watch based on who the guests are.