Late Night with Jimmy Fallon (NBC)

Late Night has always skewed younger, audience-wise, than the more traditional Tonight Show. O’Brien’s predecessor, David Letterman, created the modern format for the late-night talk show -- blending subversive humor, cynicism, and off-color jokes about politics and sex. The result is more for left-leaning college kids than the mainstream, middle-aged audience.

O’Brien adhered to the same pattern, and Fallon is following in his footsteps, though he’s tried to inject even more youth culture, notably by bringing in popular hip-hop group The Roots as his house band. Fallon is an affable host, charming and often witty, but he doesn’t always seem as quick on his feet as Letterman or O’Brien, and, as a newcomer to the gig, he occasionally seems a bit starstruck. But those issues could be related to his relative inexperience as a host -- before landing the job he was best known for his stint on Saturday Night Live -- and he does seem to be growing into the job.