Earlier this evening my older daughter and I watched part of a television biography of Carol Burnett. My daughter recognized Burnett from her role in the movie Annie, and watching excerpts from several skits on The Carol Burnett Show, said, "I wish that show was still on. It looks funny."
My wife and I both recall The Carol Burnett Show—which ended in 1978, when we were about the same age as our kids are now—as a fun shared childhood experience, like M*A*S*H and The Mary Tyler Moore Show, as well as NOVA on PBS. In Canada, the program was always sponsored by Kraft Cracker Barrel cheese; in retrospect, the incredibly earnest, low-key ads for the cheese are almost as funny as the program itself, and are inextricable in our minds from Burnett.
What TV will our kids remember in a similar way? We do watch some together, so perhaps MythBusters, Survivor (which the girls watch with their mom), and That's So Raven fit the bill. We'll know in another 30 years.