It always comes as a surprise when an actor leaves their hit TV show voluntarily. In spite of having solid ratings with networks and critical acclaim, some stars have left steady jobs to focus on something else entirely.

Whether a show is able to continue without them, is another story.

We have compiled a list of actors that have left their TV roles far too soon by there own choice. Everyone here, had an unexpected exit that would leave executives scratching their heads about their dramatic departure.

Michael Weatherly, NCIS

For 13 seasons, Michael Weatherly was known as Very Special Agent Anthony DiNozzo on NCIS. As one of the original cast members of the CBS hit show, Weatherly was also a fan favorite with his comedic timing and endless movie references.

When Weatherly announced his departure from the show halfway through Season 13, everyone was caught by surprise.

Writers were able to wrap up his story lines and leave room for future guest appearances for the actor.

His decision to leave was to pursue new acting opportunities which later landed him the lead role on the CBS drama, Bull.

Steve Carell, The Office

For 7 years Steve Carell brought Michael Scott to life with constant, inappropriate jokes, and painful awkwardness.

In 2010, Carell decided not to renew his contract, so the writers gave Michael Scott the send-off of a lifetime. It was one of the saddest, most memorable moments of the entire show.

After the show Carell went on to star in numerous successful movies including Despicable Me, The Big Short and Crazy, Stupid, Love.

The Office didn't fare well without him, however. The series continued for 2 more seasons, but it was clear that the hole Carrell left could not be filled.

Rob Lowe, The West Wing

Rob Lowe played the idealistic go-getter Sam Seaborn on The West Wing. His character was eventually written out, although he did return briefly for the show's series finale. Lowe originally suggested that there was no more room for Sam's character to grow, but there was speculation that he left because of salary disputes.

The show initially started off with Sam as one of the primary characters, but his story eventually dwindled down in the first 4 seasons. Same goes with Lowe's salary. When he started he was the highest paid cast member, but lost that status over time.

The show continued for another 3 seasons after Lowe's departure and continued to rake in critical acclaim. Even though Lowe left during the height of the show's popularity, both the series and the actor fared well after his surprising departure.

Find out which Home Improvement, Cheers and Criminal Minds actors left the show surprisingly on the next page.

Jonathan Taylor Thomas, Home Improvement

As a standout character on Home Improvement Jonathan Taylor Thomas quickly became the ultimate '90s heartthrob. In 1998, however J.T.T. decided to leave the show that was preventing him from getting a traditional education. So he left to enroll in Harvard.

Writers sent his character, Randy, to study abroad program in Costa Rica and he briefly made a return for the Season 8 Christmas episode. By that point, though the show was practically a sunken ship already.

Topher Grace, That '70s Show

Everyone remembers Eric Forman on That '70s Show, so his decision to leave the show send shockwaves to fans across the world. It's not clear whether the actor wanted to to pursue other acting opportunities or he simply wasn't getting along with other cast members.

After 7 years as playing one of the lead roles, writers sent the Eric character to a teaching job in Africa.

The show only lasted 1 more season after Grace's departure, because clearly things weren't the same without him.

Shelley Long, Cheers

As Diane Chambers on Cheers, Shelley Long enjoyed the success of the show for 5 years. In that time she was nominated for an Emmy 5 times and walked away with the award in 1983. The chemistry she had with the show's leading man, Ted Danson was undeniable. When their characters finally got together, Long decided to call it quits. She wanted to spend more time with her family and pursue a career in film.

Long returned for the series finale, but she never enjoyed the same level of success making movies as she did as Diane on Cheers.

Mandy Patinkin, Criminal Minds

I think everyone can agree that Special Agent Gideon was an FBI gem. In spite of being an integral part of the Behavioral Analysis Unit, Gideon's character only lasted until the beginning of Season 3.

Mandy Patinkin later admits that he had grown wary of the gruesome storylines on the show that he was relieved by his character's departure. He even went so far as to say that joining the show was huge mistake since he believed the series would be very different from how it turned out.

However, Patinkin left on a good note, leaving the cast memories apologetic letters wishing them  and the show the best.

The show has fared fine since his departure, particially thanks to the recuitment of David Rossi (Joe Mantegna). Rossi stepped into the leadership role and helped take the BAU to new heights.

Patinkin went on to star on Homeland, which has earned him both an Emmy and Golden Globe nominations for his performance in the show.

Which character do you miss the most?

Source: Zimbio