NBC likes Jay better than it did Conan or Dave. To follow him, Dave liked two Craigs and a Tom. Jimmy succeeded Conan, who succeeded Dave, who succeeded Tom.

But none of these men has managed to get late night absolutely right. In a situation like this, it is generally useful to ask, "What would Frankenstein do?" The scientist, in his lab, stitched together human parts to make a new creature. But his tragic mistake was in rejecting, rather than loving, his creation.

If we could actually assemble a character from the pieces we propose below, we would adore it to an extreme. We would stay up late, laughing, more often. The parts:

Ferguson's monologue

Deliriously loopy and free-form, Craig Ferguson's bit is the single most exciting thing in late-night TV. Tune in and you might be greeted not by the Scottish host, but by Sid, a prolifically profane rabbit puppet. You might see the monologue extended to half an hour, even when there's a guest as high profile as Scarlett Johansson waiting. There's a recklessness to it, a sense of danger reminiscent of first-rate improvisational theater.

O'Brien's sensibility

Conan O'Brien has had all the publicity of late, brilliantly parlaying NBC's take-back of the "Tonight Show" gig into sympathy and a sold-out national comedy tour. But he'll just never be as easy to watch as natural showmen such as Kilborn and Ferguson. Still, what O'Brien and his writing team did with "Tonight" was fresh and format-challenging; if only people had paid attention. This fall, as the big cheese at relatively low-profile TBS, he'll presumably have even more room to play. The results should be fascinating.

Letterman's interviewing

The comedy these days on David Letterman's CBS "Late Show" is, at best, jogging at an easy pace. It's not until he starts talking to guests that his brilliant mind, seemingly, re-engages. He routinely turns these pro forma sales calls into moments of character revelation. Letterman's fawning over female guests looks bad in light of revelations about his private life, but the flirting is often mutual.

Fallon's subject matter

Jimmy Fallon can be charming to a fault, his shrugging boyishness a ready crutch. But give him credit for bringing to late night a genuine engagement with Internet culture and an interaction with popular music deeper than just having bands come and play their latest.

Leno's ratings

Jay Leno is a shell of the once-great, ticked-off comic who was Letterman's best guest back in the 1980s, when Letterman was, all by himself, the closest we've had to the embodiment of the ideal, modern-era, late-night host. But Leno does get the most viewers of any of them. When you are constructing a perfect talk-show host, the ability to please many of the people much of the time is nothing to be underrated.