Is it life or death for Gregory House in Fox series finale?

For fans of quality television, it may be the most important question of all.

How do you know when it's time for a long-running TV series to call it a day, already?

The question arises as Fox's House prepares to ride into the sunset tonight after nearly eight years on air, concluding its story of a tortured, misanthropic doctor who tackles cases like a medical Sherlock Holmes with a two-hour finale.

The final episode's title, "Everybody Dies," calls back to the premiere episode "Everybody Lies," while also serving as a perfect summation of lead character Gregory House's sunny attitude.

Producers won't say much about what happens in tonight's finale, beyond noting the return of Allison Cameron (Jennifer Morrison), Remy "Thirteen" Hadley (Olivia Wilde) and the doctor who killed himself, Lawrence Kutner (Kal Penn). The first hour, "Swan Song," is a retrospective on the past eight seasons, with "Everybody Dies" as the hourlong final finale.

Count me among those former fans who felt this show should have shuffled off the schedule a few years ago.

I once incensed a friend (okay, he was former Tampa Bay Times metro columnist Howard Troxler) by showing him how, years ago, the medical stories on House were so formulaic you could set your watch by the symptoms patients endured (a seizure by 15 minutes in; bloody vomit by 30 minutes in; a life-threatening cure that won't work by 40 to 45 minutes in; actual cure by 10 minutes before the episode's end).

Thankfully, the show has gotten better. Still, as the most compelling part of the series also got outlandish — consummating House's long-standing flirtation with rigid boss Dr. Lisa Cuddy (Lisa Edelstein) in an awkward romance which ended when cost-cutting forced the show to eliminate her character — there were fewer reasons to tune in each week.

Series star Hugh Laurie, who earns a reported $700,000 per episode molding his British tones into House's angular American bark, gave a different reason for the show's ending on NPR's Fresh Air with Terry Gross.

"The character is so inherently self-destructive to the point of being virtually suicidal, that a fictional character cannot sustain that suicidal tension indefinitely," Laurie told Gross. "You can't have a man on a window ledge threatening to jump forever. At some point, he's got to jump or get back into the building, because the crowd below — who are either urging him to jump or not jump — eventually will lose interest."

Laurie has a point. House is such an extreme antihero, even in a TV universe filled with them, that keeping him entertaining while pushing the boundaries of his pathology for 177 episodes was nothing short of a miracle.

U.S. television could take a hint from the Brits, who often limit their most popular series to bursts of three, four or five seasons, walking away from even popular series such as the original version of The Office after three seasons.

Instead, American television milks a popular show until one of three things brings it down: a lack of creative ideas, a drop in the ratings, or escalating costs. Or, sometimes, all three at once.

That, for example, is what killed ABC's Desperate Housewives, a show that started as a cultural phenomenon and finished its run last week with so little buzz some critics were asking in finale stories, "Who still watches Desperate Housewives?"

But Laurie promised the Associated Press that House's finale would have no such saving graces. "Is he gonna step forward or step back?" said the actor of the episode, which features House treating a drug-addicted patient. "Is it life or is it death? I can say no more than that."

The only thing it really can't be, given Gregory House's acerbic legacy, is boring or sentimental.