The Fall of Ratings King 'American Idol'

was once the hottest show on American television. But after 13 seasons and more than 400 episodes, the once-popular reality TV series is slowly turning into a ratings joke. To be fair,

is still one of the higher-rated shows. More than

tuned in to last week's episode. That's more than virtually

on

, including

,

,

,

,

and others that have been renewed for next season. In the ‘80s, it wasn't uncommon for the top shows to receive 20 million viewers. But in today's world, there are more channels producing original programs and more overall viewing options. A recent episode of

, which is arguably the

, attracted 17.8 million viewers. This does not include the number of people who may have watched the show on CBS.com.

Nonetheless, those ratings are a far cry from the

who watched

in the ‘80s. That's what made

so special. Like it or loathe it, few viewers could escape its wrath. The show dominated ratings for several years and put Fox on the map as a real player in network television. Just three years ago the show was capable of pulling in as many as

for its season finale. Previous

finales have been watched by as many as

.

Surely this year's finale will draw in more viewers than the current week-to-week results. But the show is unlikely to achieve ratings that are anywhere near its all-time high. It may also be unable to pull in ratings that comparable to last year's season finale, which was only watched by

. Two years prior, more than 29 million people tuned in to see the last episode. At the same time, NBC's

-- another music competition -- has become tremendously popular. The premiere ratings have increased every year since the series began in 2010. The latest season set a

for the show with more than 15.8 million viewers. That's nowhere near the all-time highs of

, but

is on a network that has only just begun to recover from a multi-year downturn.

, on the other hand, is on a network that has been declining for several years. Fox has high hopes for the return of one of its most successful shows:

. After failing to produce a script that was up to snuff, Fox decided to delay the proposed

movie. Not long after, the network began toying with the idea of bringing the series back to TV in a new format. It wasn't designed to replace the

film, but would instead serve as a continuation of the series. One show is unlikely to save Fox, however. And even if it could, that doesn't mean that

will regain its momentum. Disclosure: