Most dramatic episodic television is boring. Or at least it becomes boring with enough episodes. Most dramas follow an incredibly formulaic plot. I think Law & Order is a great example. The first half of the show is with the cops, then the second half is with the lawyers. Yeah yeah, sometimes they go back to the cops for more evidence before finishing with the law-talking guys, but the recipe is still the same. Cops then lawyers. Even the spin-offs with Special Victims Unit and Criminal Intent are quite formulaic. All the CSI varieties suffer dearly from this same problem and I'm not just talking about Horatio's sunglasses fetish. Crime happens, look for evidence, analyze evidence, arrest one to three wrong suspects, find more evidence, let crime scene investigators do interrogations (wtf?), analyze more evidence, make a breakthrough, catch bad guy, episode ends, assume shaky forensic work holds up in court. Enhance it!
The other problem with the CSI universe is the social impact that has led to the CSI effect. (I cannot call it a cultural impact, because that would imply the show has any sort of real culture.) Perhaps this line from Superbad sums it up best:
When I first joined the force I assumed there was semen on everything. I thought there was a semen database that had every bad guy's semen in it. There isn't. That doesn't exist. It'd be nice. Like the crime scene today. If the man had ejaculated and then hit you in the face we would have a real good shot at catching him.
Edit: I realize that I used a rather ridiculous quote, but it was a pretty ridiculous movie. The point, of course, is that we are not constantly shedding the large quantities of skin, hair, or fluids all over everything all the time like they frequently depict in CSI.
Reasonably quality shows like House M.D. are predictable in their own right: Patient is sick, the team struggles to diagnose without more symptoms, House is a jerk and mocks their terrible theories, they try treatment anyway, more symptoms occur, they try other treatment(s), patient nearly dies, House is a jerk again, they stabilize patient, running out of time, someone (usually Wilson) says something random that gives House the answer, House cures patient, House is still a jerk. Don't get me wrong, I still like the show, but the arc of any individual episode is predictable. The hook of most good shows is the overall story lines and character development. That's why I liked the short-lived Life and the still-airing Burn Notice. The similarity of these three previously-mentioned shows is that still do retain a reasonable amount of serial-ness to them and almost every episode can stand alone if necessary. Each week, House has to cure the patient, Life has to catch the crook (it's a cop show), and Burn Notice needs to help fix someone's problem.
Hmm, the structure of that last sentence reminds me of a line from The Simpsons:
Homer: I think the government has better things to do than to read my mail.
(cut to agents reading letters from a bag called 'Simpson Mail')
FBI Agent: Most people write letters to movie stars. This Simpson guy writes to movies. "Dear Die Hard. You rock. Especially when that guy was on the roof. P.S: Do you know Mad Max?"
The value in the standalone format is that it makes the shows make easier to syndicate later in their life cycles. Syndication is a big deal for producers and distributors. It gives shows additional lives and a long revenue tail. This is why shows like Lost and 24 or so hard to get made. For all the critical success and pretty strong commercial success those shows have had, their non-traditional formats will make future syndication more difficult than a typical show. 24 may be too serial (especially its first couple seasons) and Lost is probably not serial enough. It's also why a casual viewer like myself cannot get into shows like that. Who has time to watch a show every single week? I suppose people with boring jobs. Oh, you say to get a DVR? Not worth the value to me, though it may have something to do with not owning a television. Get a television? Never!