A couple of clarifications, explanations, etc. to why certain TV questions come up:
-- There is a definite geek factor involved when it comes to stuff like Buffy, the Trek universe, Simpsons, Dr. Who (back in the day) etc. Not only are players naturally drawn to shows like that, but since we're supposedly good at retaining knowledge and asking questions accordingly, it only makes sense that there would be a nearly savant-like quality to the questions.
-- Game shows are probably asked a bit much more in relation to all the other shows out there. It makes plenty of sense, however. We're playing a game show (albeit one that isn't televised) and given our interest in knowing things and showing off our knowledge, one of the best outlets for that is screaming at the TV while shows are going on. Thus, it's a natural match to see a bunch of game show questions written.
-- Crappy shows like My Mother the Car show up because of the "trashy" factor. It also helps that TV Guide had it on its 50 Worst TV shows list. Another thing that should be taken into consideration when stuff on short-lived TV shows, one-hit wonder musical artists, etc. shows up maybe a bit more often than others is that they often have short listings in different reference books, Web sites, etc. It's easy to glean enough information to write a tossup with a gettable answer. Yes, we can be lazy, and it's easier to condense a listing in some TV or music encyclopedia than it is trying to find different sources to layer a question.