Good-looking corpse: yea or nay?

Something to keep people occupied while I'm off writing about mobsters in tacky track suits:

Between the "Lost" producers declaring their intention to end the show sooner rather than later, Ron Moore's comments that "Galactica" is entering its third act, and "The Sopranos" and "The Shield" in various stages of wrapping everything up, I'm wondering what people's thoughts are about when/if their favorite shows should call it quits.

It's hard to be more fixated on a show than I was with "NYPD Blue," but I was ready for that show to end long before it did. I feel like the last few seasons, while competent enough, dragged down my opinion of the series as a whole because they kept hitting the same notes that had been played so beautifully in the early seasons. At the same time, I kept getting e-mails through my website from people who were anguished that things were coming to a close; they couldn't get enough of their weekly Sipowicz fix, no matter how watered-down or repetitive it might have been. A few of them even asked me what they could do to change ABC's mind about the cancellation.

We all know that "X-Files" would have been better off ending on Chris Carter's original five-year plan, and I'm sure some of the weak spots in latter-day "Sopranos" have come from David Chase and company trying to stretch out their material past the point of usefulness. I loved the last season, but at the same time I could see how the episodes began losing their momentum halfway through -- right around the point when the writing staff realized they would be doing another batch of episodes after that one. And even "The Shield," which has been remarkably consistent throughout its run, bothers me from time to time with the fact that Vic keeps narrowly escaping justice, year after year.

So, a few questions for the peanut gallery:

1. On average, would you rather a show you like overstay its welcome just so you can spend more time with the characters, or do you subscribe to the old Branch Rickey "better to trade a player one year too early than one year too late" philosophy?
   
2. In the past, what shows do you like that have suffered the most from sticking around too long?
3. Have any shows that you love seemingly overstayed their welcome, only to have an unexpected creative resurgence towards the end? (I'd put "Cheers," "Frasier" and, to a certain extent, "NYPD Blue" on that list.)
   

Fire away. Rerun season's a good time for open threads.