Here's a graph
from the marketing research firm National Media Research, Planning, and Placement
of how the audiences of cable television networks skew in terms of party (Democrats to the left, Republicans to the right) and likelihood of voting (highest turnout at the top).
The cable network with the most Democratic-leaning audience is Soapnet, while the most Republican audience is that of Fox News. The network with the highest election turnout rates is the Golf Channel (just as golf fans have the highest turnout rates among fans of all sports, as shown in my latest Taki's Magazine column
). VH1 viewers have the lowest turnout rates (this is among adults, in case you are wondering).
NMRPP also has created a graph at the top of p. 4 of this report
that shows the political leanings across TV (cable and broadcast) of the audiences for various program formats (national news, documentaries, comedies, science fiction, sports, and so forth). When you include broadcast networks, most genres' television audiences skew more Democratic and more apathetic.
Update: TGGP has put up that television format graph here.