There's never anything good on

A new take on the Drake Equation with respect to television.

The number of good shows on right now can be expressed as follows:

N = s * c * i * t

Where:

s is the number of shows currently on a typical TV channel
c is the number of channels available in your area
i is the fraction of shows you find interesting
t is a fraction representing the current timeslot as a piece of the day

Personally, I have 4 free-to-air channels available and I estimate that I find about 5% of television shows interesting. If a day is divided into 48 half-hour slots, then t is about 0.02. If these numbers are representative, I should feel compelled to spend only about 6 minutes per day watching television (c * i * t * 1 day), and that's before I decide which particular show to watch. And if a third of the time is ads, I'll only get 4 minutes of actual content.

If TV shows are split about 50-50 between one-hour and half-hour shows, then we expect to see 56 one-hour episodes per week and 112 half-hour episodes for a total of 168 shows on a typical TV channel. 168 * 4 * 5% * 0.02 = 0.672 good shows on right now.

Mokalus of Borg

PS - So I guess you have about a 2 in 3 chance of something good being on.
PPS - I haven't taken all factors into account, though.