John Stamos Triumphantly Returns to Television on 'Glee'
WATCH John Stamos Causes Drama on 'Glee'

For Denise Dorman, a fan of the acclaimed Fox television show "Glee," the series' new season has provided a huge bonus, and his name is John Stamos.

"My husband and I are 'Gleeks,' and seeing John Stamos go from 'ER' in a more dramatic, serious role, to the goofy dentist he'll play on 'Glee' – someone so against his typical character type – is something we are really looking forward to," said Dorman, a marketing professional in Carpentersville, Ill.

Stamos is just one of a hot group of actors – small-screen icons with several pop culture-legacy series under their belts – whose every move on television is tracked and followed by adoring fans.

Stamos's juggernaut began back in 1987 when he played Jesse Katsopolis on "Full House" for an eight-year run. He's starred in "Thieves," "Jake in Progress," and the crowd-pleaser "ER."

John Stamos guest-stars on 'Glee'

Now Stamos is back on network television in the recurring role of dentist Carl Howell on Fox's hit show "Glee." In tonight's episode, Dr. Howell's expertise provides the creative juice behind the show's anesthesia-fueled, Britney Spears-centric dream sequence.

In an interview published in USA Today, Stamos said that in other shows he was asked to be "the cool guy or the charming guy. This guy [Dr. Howell] wants to be that guy, but he misses the mark."

Dr. Carl Howell (John Stamos) checks out Will's (Matthew Morrison) teeth in the "Britney/Brittany" episode of "Glee." (Adam Rose/FOX).

Although Stamos's dentist character may have the lovable loser gene, casting proven and durable series' actors and actresses in new series is often a successful strategy.

"If fans like a particular actor in a certain series, they'll tend to follow that star's new series," said Gloria Smith, president of Media Connection, a media-buying agency, in Rochester, N.Y. "A show's popularity determines ratings, and ratings help determine what television affiliates can charge companies to buy air time for commercials."

Jimmy Smits's career has also been fueled by ground-breaking television series. After establishing his acting chops on "L.A. Law," Smits got the star-making role of Detective Bobby Simone in "NYPD Blue." Stints on "West Wing," "Cane" and "Dexter" followed. Now he's starring on CBS's "Outlaw," portraying a former Supreme Court justice who starts his own law practice.

Keri Russell.

Keri Russell and her angelic blond ringlets became an audience darling in 1998 when she starred in "Felicity." Now she's in Fox's new offering "Running Wilde," playing an environmental activist.

Michael Chiklis, with a string of hit series behind him – "The Commish" from the early nineties, "Daddio" and the gritty, ground-breaking cop show, "The Shield" – is now the star of "No Ordinary Family," debuting tonight on ABC.

Chiklis plays Jim Powell, the head of a family whose members suddenly find themselves in possession of certain superhuman powers. His wife is portrayed by Julie Benz, whose character on Showtime's "Dexter" was brutally murdered last season.

Michael Chiklis.

The New Comers

Like Benz, other upstarts hope they're well on their way to establishing thriving television careers by creating iconic audience-pleasing characters.

Daniel Dae Kim, who had recurring roles on "24" and "ER," hit pay dirt when he played sympathetic, affable Jin on "Lost." As "Lost" ended its run, he quickly got snapped up to play Detective Chin Ho Kelly on CBS's new series "Hawaii Five-O."

Michael Raymond-James.

Michael Raymond-James is another recognizable face gunning to become a household name. In a memorable turn on "True Blood," he played the murderous Rene. Now, he portrays a private investigator on FX's "Terriers."

Anne Dudek is also rising through the ranks. After meaty recurring roles on "House," "Big Love" and "Mad Men," she landed the big-sister role on "Covert Affairs," which recently finished its first season.

It's not only loyal fans who keep an eye on their favorite television actors. Networks know that certain celebrities add huge value to their programs.

Anne Dudek.

"You can enforce a brand's equity – the same goes for a television program – through a celebrity's equity," said Matt Delzell, a director in the celebrity-endorsement division at The Marketing Arm, in Dallas, Texas. "And if your brand awareness is low – if you're a new product on the market – a celebrity can play a big role in awareness-building."

It sounds like a foolproof strategy, but audiences can be fickle.

"Viewers often form relationships in their mind with their favorite character," said Smith. "If the actor's new character is dissimilar to the fan's favorite one, the viewer may a hard time accepting the actor in that role. It's the reason so many actors are type-cast."