Doctor Who: The TARDIS Has Always Been, Will Always Be The Show's Star
The TARDIS is what truly defines Doctor Who - the most faithful companion, the MVP, the Doctor's true love, and the REAL face of the show.
Oh, look, it's a half-hour Doctor Who video about the TARDIS. It's about time. Its name is an acronym for Time and Relative Dimension in Space. It's a time machine but also a spaceship. The TARDIS is cool. It's the ultimate high-concept gimmick that defines Doctor Who.
The TARDIS is the real poster child for the show. It's the most unique ship in Science Fiction television and uses the British tendency to take the mundane and imbue it with surrealism and meaning. Blue police boxes were common all over the UK until the 1970s, serving as makeshift shelters, stations, and holding cells for bobbies on the beat. It was created out of the expediencies of a low budget and what was practical for a British TV show when CGI didn't exist. The external TARDIS itself was and continues to be an easy prop to build – it's just made of wood like real police boxes. The interior was always a studio set. The TARDIS cockpit main set was initially simple and cheap, almost bare and spartan, but improved production values and rising budgets have made it increasingly elaborate, with the next version starting from the Doctor Who 60th Anniversary Specials rumoured to be the largest and grandest to date.
The TARDIS has fired up the imaginations of Doctor Who fans more than the sonic screwdriver ever it. It wasn't a slick new slick but a rickety old model that the Doctor stole and could barely bring under control. It hardly ever took them where they needed to go. The classic era of the show hinted that the TARDIS was alive. There were subtexts about the Doctor's relationship with the TARDIS that the writers of the 1990s Virgin novels started to expand on and that has been made official by Russell T. Davies and Steven Moffat in the modern era. It was Neil Gaiman, under Moffat's watch as showrunner, who got to write as official canon that the TARDIS was female and loved The Doctor, that she exists through all of Space and Time and can see it all, and she always took them where they needed to go, to where their help was needed.
Doctor Who: The TARDIS Really Is Everything
The TARDIS is a totem. The TARDIS is the wardrobe from The Lion, The Witch and the Wardrobe, a magic box, and a magic portal to magical places. The TARDIS is the Doctor's home. The TARDIS is the Doctor's safe place, their safe space. If you want to get really symbolic, the TARDIS is the Doctor's womb. They always return to it. When they're dying, they always need to be in it or near it to regenerate. The TARDIS is the Doctor's one true love. The Doctor may love their companions and treats them with varying degrees of condescension, but the TARDIS will always be the Doctor's most faithful companion. You could argue that The Doctor was smart and cunning enough to figure out other ways to travel without a TARDIS, but the image of a modest, tiny blue box that a crazy but kind alien travels in to help people is the defining concept of Doctor Who.