A channel that airs mostly 1990s cartoons, including my favorites, The Powerpuff Girls classic, SpongeBob SquarePants and maybe they could have the USA premiere of the English dub of the magical girl anime, Powerpuff Girls Z on this channel. Of course, the hardest part is getting Time Warner Entertainment (and other companies, like Viacom and DHX) to supply the programming. The people who own these programs are licensing them to places like Hulu, instead of giving the classic cartoons their own digital subchannel. I think they should create a channel similar to Mexico's Canal 5* that airs cartoons, movies, and sports, as well as educational programming for younger viewers during the morning and afternoon, while the nighttime hours would consist of programming aimed at adults, like Law & Order, for example.
If I worked in the field of broadcast engineering, I'd bring back Fond du Lac, Wisconsin's KFIZ-TV (which existed from 1968 to 1972 as Wisconsin's first independent TV station and sister station to KFIZ AM radio Fond du Lac) as KFIZ-HD, with the purpose of making youth television programming accessible to everyone in Wisconsin during the day, and provide an entertaining alternative to the educational stuff provided by PBS Kids or Qubo, although I would devote a few hours each day to educational programming to earn some brownie points from the FCC. The station would have its main operations in Fond du Lac with repeaters in Green Bay, Milwaukee, Madison, Wausau, La Crosse, Eau Claire, and Rhinelander, as well as an Upper Peninsula repeater in Escanaba, Michigan, serving Marquette and the surrounding area.