I don't rank these things on an emotional level, so I wouldn't expect that type of list to be the same.

In addition to what I've previously mentioned, I also hold the show in high regard on artistic merits. At the end of the day that's what film making is.

But what I'm not sure of is what the ending of any show has to do with its quality. A superb ending can be had on an otherwise crappy show, likewise a fantastic show can have a horrid ending. Or somewhere in-between. The fact that something is great doesn't mean it can't falter and visa versa (once, twice or three times a lady).

I give some examples of various of the above issues in no particular order:

Lost
Seinfeld
Medium
The X-Files
24
Heroes
Twin Peaks

It's just chance that I listed only shows that have ended their runs.