It may be hard to imagine your favorite shows any differently than the way you do, but there's a chance that those programs that you know and love may not have turned out the way they did.

Yes, it's true -- on the road from pilot to full-blown television series, major and minor roles are often changed, important plot lines are scrapped or rewritten and the theme songs you'll eventually be humming can sound a whole lot different. Here’s a look at some very popular shows and the surprising footage from their unaired pilots.

  • 1

    'Saved by the Bell'

    Before 'Saved By the Bell,' there was 'Good Morning Miss Bliss,' the NBC primetime sitcom that was initially a vehicle for 'Parent Trap' star Hayley Mills. And before 'Good Morning Miss Bliss,' there was this 1987 never-aired version of the pilot, which featured a pre-'Beverly Hills 90210' Brian Austin Green. And Zack Morris is nowhere to be seen, either.

  • 2

    'Married...with Children'

    Back in the late 1980s, Fox caught a lot of heat for 'Married...With Children,' which critics claimed was nothing but trash TV. But audiences loved The Bundys. Would they have still felt the same way if Bud and Kelly were played by Hunter Carson and Tina Caspary, the actors who portrayed them in this unaired pilot? The producers wisely recast the roles, as Carson is super annoying and Caspary -- who you might remember from 'Can't Buy Me Love' -- is a generic Alyssa Milano clone.

  • 3

    'The Munsters'

    They were America's most misunderstood family, but reaction to 'The Munsters' may have been vastly different based on this intro, which will have most fans saying, "Who are these guys?"

  • 4

    'Gilligan's Island'

    Just sit right back and you'll hear a tale...of a show that vaguely resembles the one you know and love. Turns out the classic theme was originally a stereotypical "Calypso" tune and Ginger and Mary Ann were "two secretaries" whose faces we don't see.

  • 5

    'The Big Bang Theory'

    Fans of this CBS comedy know that Sheldon has no interest in sex, which makes the scene in this unaired pilot all the more fascinating: he's donating sperm. Producers scrapped that gag and went with his asexual personality, which worked out pretty well, considering Parsons has won a pair of Emmys for his work.

  • 6

    'Three's Company'

    No Jack Tripper? No Chrissy Snow? No Janet Wood? No way. This intro shows just how different the show could've been. While John Ritter was the main character, Joyce DeWitt and Suzanne Somers were not cast and Jack (named David in the pilot) was going to live with women named Jenny and Samantha. The Ropers, however, did survive the pilot and went on to become a key cog in the show's success. And side note: what's with the theme? Thank goodness someone decided to add lyrics!

  • 7

    'Star Trek'

    While 'Where No Man Has Gone Before' did technically air as episode three of 'Star Trek,' it exists in a completely different form as a lost pilot. Two pilots were initially shot for the classic 'Star Trek.' The first attempt, called 'The Cage,' featured Captain Pike (Jeffrey Hunter) at the helm of the Starship Enterprise. NBC scrapped it, keeping only the character Spock and the actors Leonard Nimoy and Majel Barrett.

    The network shot the script 'Where No Man Has Gone Before,' which featured Captain Kirk and the rest of the familiar Enterprise crew, as the second pilot. But several elements are different than what would air, such as the classic theme song and the use of onscreen text to denote when an new act starts. The first cut also features a few extra scenes that weren't shown when 'Where No Man Has Gone Before' debuted as episode three of the series. ('The Man Trap' was the first 'Star Trek' episode to air.)

  • 8

    'Buffy the Vampire Slayer'

    Before 'Avengers,' Joss Whedon hit the big time with 'Buffy the Vampire Slayer.' In this clip from the original pilot, the Scooby Gang go to a different high school and Alyson Hannigan isn't playing Willow. (She's played in the pilot by the wonderfully named Riff Regan.) Who knows, if Riff had held on to the part maybe she'd be starring on 'How I Met Your Mother' right now.

  • 9

    'Angel'

    It's hard to believe there was an unaired pilot, since this was a spinoff of 'Buffy the Vampire Slayer' with a built-in fan base. That's the case, however, and the opening gives viewers plenty of backstory into just who Angel is. It's also darker, featuring scenes of Angel drinking the blood of a murder victim.

  • 10

    'All in the Family' (#1)

    'All in the Family' was a groundbreaking show, but first it had to figure out its cast, which is why there were two pilots that never made it into our living rooms. Initially the show was called 'Justice for All,' with an intro that reminded viewers back in 1968 that it was "suggested for the mature audience." Note the different actors who played Mike, Gloria and Lionel.

  • 11

    'All in the Family' (#2)

    In 1969, one year after 'Justice for All' failed to take off, a new take on what would become 'All in the Family' surfaced, this time under the title of 'Those Were the Days.' The "suggested for mature audience" disclaimer remained, while a different crew was brought in to play Mike, Gloria and Lionel. Producers kept hammering away by eventually casting Rob Reiner and Sally Struthers and the rest, as they say, is history.

  • 12

    'Family Guy'

    The heart of Seth MacFarlane's animated series looks the same, particularly Stewie's disdain for Lois, but the production quality isn't quite up to snuff and it's weird to hear Chris' "dumb guy" voice. (Lacey Chabert also voiced Meg during the first season.) And there's no Quagmire, although you can hear his voice in one of Peter's friends. Still, fans will find this to be quite interesting. And, if you look closely, you'll see Peter's wearing thicker glasses, giving him a nerdier Poindexter look.

  • 13

    'Desperate Housewives'

    Sheryl Lee of 'Twin Peaks' fame was originally cast as Mary Alice, the deceased housewife who narrated the ABC soap. Had she kept the role, Lee would've played two dead characters on two hit shows. But the producers decided her performance didn't work, and replaced Lee with actress Brenda Strong. (Actors Kyle Searles and Michael Reilly Burke were also replaced by Jesse Metcalfe and Steven Culp in the roles of John Rowland and Rex Van De Kamp.)

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