I watch the Daily Show and the Colbert Report. They pack just as much humor into 30 minutes as the other guys deliver in twice the time. I used to watch Letterman's opening monologue and his top 10 list, but once the Colbert Report hopped in after TDS I was lost forever.
As for Leno's prime time show, I think the opening killed it. That blaring big band sound made me reach for the remote before I knew what was on. It sounded so dated. I though the Merv Griffin show came back from the dead. I wonder if that show failed because it was poorly packaged.
I did sit through Jay's monologue once and didn't find him funny at all. I don't know if he's got bad writers or if he's egotistical enough to think he can write his own material but the jokes were lame. I've never been a big fan of his delivery.
I'm not overly impressed with George Lopez but he's interesting. His opening monologue has been rough when I watched but I think he plays off his guests better than other late night hosts.
I secretly hope that Conan and Letterman work out a deal where Conan moves to CBS so Jon Stewart gets stuck on TDS forver.