By TV shows don't always get commissioned, filmed and put on air straight away. Sometimes, there's a long development process where niggling issues are ironed out.
Usually this occurs before the cameras get involved, but often pilot episodes are filmed to a lukewarm reaction at best.
These are the times where whole episodes were shelved and re-made, whether it was to replace underwhelming actors, shift the tone, or change the whole concept altogether.
Game of Thrones
If you watch the first Game of Thrones episode, there are certain inconsistencies that are hard to ignore once you see them. For instance, Jon Snow and Robb Stark appear clean-shaven for half the episode, and Tyrion has a rather dodgy wig.
That's because the show had to re-shoot around 90% of its pilot episode. Producers have said that it'll likely never be shown, as it was rather shoddy in comparison to the slick production we know and love.
Test audiences apparently didn't understand the relationships between the main characters, including not realising that Jaime and Cersei were brother and sister, or that Tyrion was a Lannister. Daenerys Targaryen and Catelyn Stark were portrayed by completely different actresses (Tamzin Merchant and Jennifer Ehle), and Theon had a blonde wig.
Seinfeld
When Jerry Seinfeld and Larry David first worked on what would become America's biggest-ever sitcom, it was originally called The Seinfeld Chronicles.
The original pilot episode was rejected by NBC, after focus groups labelled it "weak". The early version didn't have Elaine, Kramer was known as Kessler, Jerry and George hang out at Pete's Luncheonette, and the theme tune is... meh.
Seinfeld and David didn't see the memo stating the focus groups' negative reaction for several years, but after they did, they hung it in a bathroom on the set of the show. Seinfeld later said: "We thought, if someone goes in to use this bathroom, this is something they should see. It fits that moment."
Family Guy
Okay, the Family Guy pilot episode isn't that much different to the final product. But the animation is so shoddy (considering that the final version wasn't great either really says something), that it's really bizarre to watch back now.
It was created by Seth MacFarlane as a pitch for show to networks, only running at seven minutes in total. Lois is blonde, Chris has a deeper voice, Quagmire doesn't exist yet, and they're all nice to Meg, what heresy!
The Inbetweeners
Before The Inbetweeners first arrived on our screens in 2008, creators Damon Beesley and Iain Morris first tested the show in 2006 under the title Baggy Trousers.
The series was completely different to what it eventually became. First of all, it was set in the 1980s, but it still would have followed four awkward teens.
A pilot was filmed with a totally different cast to The Inbetweeners, and a few other big differences. Foul-mouthed joker Jay is nowhere to be seen, replaced by another character named Lee. The pilot was never aired and has never been released in full.
