Smarmy Host

A related trope to Kent Brockman News and Hates the Job, Loves the Limelight, this is the game show or sport event counterpart. You know the type, slicked hair and an equally slick personality with a big helping of flaming narcissism on the side. They'll crack lots of jokes of the Witty Banter type, but you always suspect they're really a Jerkass, and you're often proved correct in that assumption as they keep the catty remarks and poorly-concealed insults flowing. In extreme cases, contestants may get the impression he's actively rooting against them, or worse, deliberately setting them up to fail.

When used in an actual broadcast, this tends to go best when said host is schooled enough in Self-Deprecation to realize that he comes off as this, and uses it to make more jokes at his own expense. In this case, he's a Jerk With a Heart of Gold whose smarminess makes him almost come off as a non-criminal Lovable Rogue. In more fantastical settings, expect this character to commentate Gladiator Games and other dangerous blood sports while treating the horrible violence and loss of life as little more than joke fodder.

Usually, you can expect a lot of overlap with Slime Ball and Smug Snake.

Examples of Smarmy Host include:

Anime and Manga

In a Non Sequitur Episode of Ergo Proxy, Vincent and co. end up trapped by a Proxy who acts as a gameshow host and has this personality to a T, and delivers exposition in the form of quiz questions.
In an episode of Martian Successor Nadesico, the various female characters on the show participated in a talent show to be the ~~new captain~~ captain for a day, and Jun and Nagare acted in the role of commentators. The latter fit into this role like a glove, being a rather jerkish Casanova.

Film

Fred Willard often plays this type, especially in Christopher Guest's movies, with Best in Show being a good example.
The jerkass Millionaire host in Slumdog Millionaire
Subverted with Corny Collins in Hairspray. He has the hair for it, is somewhat self-absorbed, but he is wholly redeemed by the fact he's not a racist, loves spotting dance talent regardless of appearance, and in fact very open to racial desegregation. When he sees Tracy dance, he hires her on the spot and laughs off Mrs. Von Tussle's threats to fire him, wishing her good luck with firing Corny Collins from the Corny Collins Show. In the end, he openly defies the villain when announcing that Inez Stubbs won the title of Miss Hairspray, citing that she qualifies per the rules, and generally functions as a Reasonable Authority Figure.
Damon Killian of The Running Man who is a Complete Monster and Villain with Good Publicity. Played by Richard Dawson, who in Real Life was the host of Family Feud at the time the movie was made.
Vince Fontaine in Grease, the host of a local rock'n'roll show which is broadcasting Rydell High's dance. He's very slick, and at one point is vigorously flirting off-camera with Marty (who is, of course, underaged).

Live-Action TV

Guy Smiley, the scenery-chewing, boisterous host of such game shows as This Is Your Lunch and Here Is Your Life on Sesame Street, is famous enough to have his own Wikipedia page.
The Joe Schmo Show had a cast of Reality TV archetypes, with the hosts' being that of "smarmy host".
Frequently mocked on A Bit of Fry and Laurie, including various real-life targets such as Noel Edmonds.
- One episode had a Double Subversion where Laurie played one of these and Fry was a highbrow author who lost patience and gave him a "The Reason You Suck" Speech about his personality, intellect and method of interviewing; the audience was laughing at this, and then halfway through he "forgot" his lines and it was revealed that the characters themselves were rehearsing the interview, the purpose of which was to stir up publicity and make the author look edgy and impressive.
Monty Python's Flying Circus has a lot of sketches based on this trope.

Video Games

In the Batman: Arkham video games, particularly in Batman: Arkham City, the Riddler presents himself as a smug gameshow host as he forces Batman to save other people from his death traps or solve tedious and frustrating puzzles for his own amusement. He never shuts up, often making snide remarks and belittling Batman for being dumber than him, only to throw undignified temper tantrums when Batman keeps outsmarting him.

Western Animation

Bojack Horseman character Mr. Peanutbutter certainly channels his fair share of this whilst hosting "Hollywood Stars and Celebrities: What do they know? Do they know things? Let's find out!". He is at his most jerkish while hosting, something that BoJack himself calls him out for; Mr. Peanutbutter then snaps and admits it's because he found out that the horse he considered a friend kisses his wife Diane behind his back, a few weeks before their wedding too boot. They pause the show to have a sincere talk, where they apologize to each other for being jerks, and Mr. Peanutbutter offers the win. Which BoJack proceeds to burn, literally, out of spite towards his opponent Daniel Radcliffe.
Weirdy aka Gustav seems to be this in The Hollow where he alternates between trolling and guiding the protagonists after they wake up in a room with none of their memories. We find out, however, that it's part of his act; when things really start going off the rails, he hides his panic while giving the kids instructions on how to win the game show safely. Case in point, during Season Two when Mira reveals that she knows his real name and tells him to knock it off with the portals, he levels with the kids that they are digital clones of the original players, made as part of the deal with the corporate sponsor. On realizing that they are sapient, Gustav defies his bosses to help the kids separate their digital world from the ones that the game show creates so that they can at least have a semblance of their former lives, while still running the show. Smarmy? Yes. Brave? Also yes. A great singer? Totally.
Alex Trebek makes a guest-star appearance in The Magic Schoolbus where he plays the host of a Show And Tell competition. He parodies himself, being a little smarmy but overall reasonable when Arnold fumbles through his demonstration onstage and starts to improvise.
Chris on Total Drama Island to humorously sociopathic levels. It gets to the point where the first season ends with him being tossed into the water, courtesy of the campers, and he gets arrested at the end of Revenge of the Island.
Beaux Handsome in Word Girl. There's also Seymour Orlando Smooth. One of the villains, he's not only smarmy, but skeezy—a corrupt host who rigs all of his game shows so that none of the real contestants have an actual shot at winning. Oh, and he uses his dazzling white teeth to stun his opponents.

Real Life

Talk show host and former sports presenter Alan Partridge.
On December first, 1976, the notorious broadcast of Thames Television's Today show aired in the London region, featuring Siouxie Sioux and members of The Sex Pistols. During what was apparently thought to be pre-show banter, host Bill Grundy, apparently drunk, made a rather explicit pass at Sioux. The resulting wordplay, which included guitarist Steve Jones swearing at Grundy, resulted in the famous "The Filth and the Fury!" headline in The Daily Mirror, and effectively ended Grundy's career.