I still prefer Letterman, mainly because he has more interaction with the audience and looks more comfortable in the host role. As an interviewer he's no great shakes, but neither is Leno. Letterman's humor is more bizarre and innovative, while Leno has the straight-ahead stand-up routine style. Leno's plunging into the audience was a direct result of his perceived lack of rapor with the crowd compared to Letterman.

One of my favorite Letterman bits was when he was informed by his announcer that his next guest was late and the announcer said "you'll just have to wait, Dave. Find something constructive to do." We then see the standard clock with moving hands to indicate time passing, then cut back to Dave constructing a small trapeze on his desk, then the clock again, and Dave is showing a cat the action of the trapeze and touching its paws to it, the clock once more, and now we see Dave smiling in satisfaction as the cat swings skillfully from the trapeze. Somehow, I can't picture Carson or Leno doing that bit.