When following one of our favorite shows over a few seasons, we become so accustomed and fond of the cast that it almost seems impossible to think of a reality in which things could be different than they are. By different, we mean a reality in which the lead stars of our favorite shows were played by completely different actors.

This is strange to think about because, in a way, it would basically change the entire dynamic and vibe of the show. In fact, the show, as we have come to know and love, would likely be completely different. Would anyone still watch the show? Would the show even be successful? Would some of our favorite actors have ever gotten their big break if it weren't for this particular part? And in what other show would it have been?

The questions are endless. This is a very interesting list that will certainly make you consider all these things. Prepare to be surprised as you read about 15 actors who were recast after the pilot episode...

Phoebe - Charmed

Interestingly, in an unaired episode of Charmed, the starring role of Phoebe is not played by Alyssa Milano. Instead, the character was portrayed by actress Lori Rom. Rumors emerged that the reason Rom left the show was that she and Shannen Doherty, who portrayed another magical sister, Prue, were bitter enemies. Both women have always vehemently denied these claims. Other rumors revolved around the fact that Rom left the role due to her religious beliefs, but once again, there is nothing factual to back up such claims. Instead, Rom has always held the claim that the reason she departed the show was due to ‘personal reasons.’ After she left, Aaron Spelling then contacted Milano to see if she would take the role, and as we all know, she accepted the offer.

Danny Tanner - Full House

In the original pilot for Full House, it wasn’t Bob Saget playing the part of Danny Tanner but was actor John Posey instead. It appears that even Posey was surprised with the sudden decision to recast the role. Everything seemed to be going well, with Full House being picked up by ABC. However, despite this success, the show’s producers still decided to try out Saget in the role and eventually recast him, giving poor Posey the boot. Apparently, the show’s producers had originally wanted Saget, but he was busy at the time, so when his schedule cleared up, they saw it as the perfect opportunity to recast him in the role and then went ahead and re-shot the pilot.

DJ - Rosanne

Did you know that Michael Fishman wasn’t the original actor cast in the role of DJ on the TV show Roseanne? Actor Sal Barone was the first actor to play the famous role, but after recording the pilot episode, he had to be cast. There are a couple of reasons why Barone was recast. The first revolves around the fact that the actor is said to have not gotten along with another star of the show, Sara Gilbert. Apart from this, Barone is said to have also had a growth spurt after the initial recording of the plot episode. For this reason, the show’s producers were worried that the actor would outgrow his two onscreen older sisters, which would have resulted in DJ losing some of his cute little brother charm. With all this taken into consideration, Barone was eventually recast with Fishman.

Catelyn Stark - Game Of Thrones

Catelyn Stark was a very prominent role in the first three seasons of HBO’s universal hit show Game of Thrones. Even the show’s biggest fans, however, may not know that the role originally went to Jennifer Ehle, who went as far as recording the pilot episode. In the end, though, Ehle chose not to pursue the part as she had just given birth to her first child. After being confronted about the show’s potential and the fact that it may be on air for years to come, the actress felt that she could not make such a big commitment after the recent birth of her daughter. As we all know, the part was then offered to Michelle Fairley, and the rest is history.

Principal Flutie - Buffy The Vampire Slayer

Principal Flutie was a much-loved part of the first season of Buffy the Vampire Slayer. The part we are familiar with was portrayed by Ken Lerner, but you may be surprised to know that the part was originally supposed to be played by Stephen Tobolowsky. The reason why the part ended up being recast with Ken Lerner was because Tobolowsky was under contract with ABC for another series, The Pretender. Talking about the experience, Tobolowsky once remarked, “Well, the series for ABC, I believe, lasted for nine shows, whereas Buffy The Vampire Slayer lasted for years. It could have made life so much sweeter through difficult times to have a steady pay check, but that’s the way the chips roll.” We think the actor might be forgetting the fact that Principle Flutie was killed off after just one season of the show. However, perhaps if Tobolwsky ended up playing the part, this would not have been the case.

Carol Seaver - Growing Pains

Tracey Gold will probably always be known for her role as Carol Seaver on the popular sitcom Growing Pains but were you aware that she wasn’t the first actress to be offered the role? Elizabeth Ward was originally cast and appeared in the pilot episode of the series, but after watching the episode back, producers eventually decided to go in a different direction with the casting for the role, and Tracey Gold ended up being offered the part of Carol and accepted the offer.

Daenerys Targaryen - Game Of Thrones

There is no doubt that Daenerys Targaryen is one of the most loved and integral character of Game of Thrones. You may not have been aware, though, that Tamzin Merchant, who played Catherine Howard in The Tudors, was the first actress cast in the part of Daenerys on the show. It all seemed to be going well for Merchant, until showrunners David Benioff and D.B. Weiss watched back the pilot episode and felt that something just wasn’t right. They were then forced to reshoot the pilot episode, this time with Emilia Clarke in the role. Merchant was then replaced by Clarke, after the latter gave an outstanding performance and appeared to be made for this role.

Benjamin Jones - The Catch

Damon Dayoub was set to play the male lead in The Catch, but unfortunately for the actor, he was let go after the series was picked up in May of 2015 and Peter Krause from Parenthood was chosen to replace him in the leading role. It was not just the male lead on The Catch that was replaced after the pilot episode but also the female lead. One Tree Hill’s Bethany Joy Lenz was originally cast as Zoe but was replaced with actress Sonya Walger after the pilot episode was reviewed. Walger had received much critical acclaim for her leading role in detective series The Killing and seemed like a safe option for the show.

Jim Walsh - Beverly Hills, 90210

You may not have known it then, but the original actor to portray Brenda and Brandon Walsh’s dad on 90210 was none other than Lyman Ward. You will undoubtedly recognize Ward for another iconic dad role, that of Ferris Bueller’s in the 80’s cult classic movie  Ferris Bueller’s Day Off. After looking back on some footage, producers didn’t really seem to think Ward was right for the part after all, so the role was recast with James Eckhouse, and all of Lyman’s scenes in the pilot had to be cut and re-shot as well.

Jenna - 30 Rock

30 Rock is another show that decided to make a change to its cast after the pilot episode first aired. Saturday Night Live alum Rachel Dratch was originally cast as Jenna DeCarlo on the much-loved show before the role was recast with Jane Krakowski and the character’s name was changed to Jenna Maloney. Dratch handled the fact that she was replaced in the role very professionally, not seeming to take it personally at all. In fact, the actress plays multiple characters on the show, including that of a cat wrangler in the aired pilot. If that’s not classy and mature, then we don’t know what is!

Inara - Firefly

Joss Whedon’s popular show Firefly, originally saw Rebecca Gayheart cast in the role of Inara. Nevertheless, the actress was reportedly fired just one day into filming of the show. The reason Gayheart was let go was because the show’s producers believed that there wasn’t enough chemistry between Gayheart and the other cast members. Eventually, Morena Baccarin (who we all know and love now due to her role as Vanessa in Marvel's Deadpool, alongside Ryan Reynolds) was cast in the role and actually went on to have great success in the part.

Toby Cavanaugh - Pretty Little Liars

Not only did James Neate portray Toby Cavanaugh in the pilot episode of Pretty Little Liars, but he, in fact, played the part for the first couple episodes. However, by the show’s third episode, Neate had suddenly vanished and Keegan Allen was suddenly in the role. The only thing that changed about Toby’s character after being switched to Allen was his last name. Originally, the Toby played by Neate had the surname Marshall, the same as his stepsister, Jenna. After being replaced by Allen, Toby took the surname Cavanaugh. It’s not really clear why the actor or the name were changed.

Sookie - Gilmore Girls

You may be surprised to hear that in the original unaired pilot for Gilmore Girls, Alex Borstein played Sookie St. James and not Melissa McCarthy. The role had to be recast as another contract prevented Borstein from taking on a main role in the show. As we all know, McCarthy went on to play the part, and we honestly can’t imagine it having been any other way. Borstein did make several appearances during the show’s seven-year run, in smaller roles such as harpist Drella, then as Miss Celine and Doris. This isn’t the only role that was changed after the pilot episode, though. During the original pilot, Dean Forester was played by Nathan Wetherington but was then eventually recast with Jared Padalecki, whom you will also recognize for his role as demon hunter Sam on Supernatural.

Sarah Braverman - Parenthood

Maura Tierney was originally cast as Sarah Braverman on the show Parenthood, but unfortunately, she had to step back from the role so that she could recover from breast cancer surgery. The show’s producers tried to accommodate her treatment by temporarily stopping production to allow the actress some needed recovery time, but her treatment plan ended up conflicting with the series’ filming schedule. A few months later, Gilmore girls alum Lauren Graham was recast in the part.

Willow - Buffy The Vampire Slayer

In an unseen pilot of Buffy the Vampire Slayer, one of the show’s main characters, Willow was actually not portrayed by Alyson Hannigan who we are familiar with in the role, but instead by actress Riff Regan. The show’s producers reportedly felt that Hannigan brought something more unique and special to the role and felt that she was a much better fit to portray the much-loved witch. So, in the end, Regan got the boot, and the part was offered to Hannigan who happily accepted it. We also think this role likely helped Hannigan get the part of Lily Aldrin in the popular TV show How I Met Your Mother later in 2005.