Being a British person it's interesting because you'd think there'd be a lot of media that gets Britain "right". We're an English-speaking nation, and culture and literature have been some of our biggest exports for a long time.
But a funny thing happens, where due to American media tending to present this really stereotyped, theme park version of Britain, our media starts to copy those tropes to appeal more to American expectations and everything gets weird. Harry Potter is absolutely terrible for this; the books are meant to be set around 1996 or so, but the muggle world of the movies seems to be a mixture of quaint 1970s cardigans, early 00s indie fashion, and stuff in fashion when the films were made. Harry Potter never feels like Britain to me. Even when they're in "the Muggle World" it feels like a fake Britain designed to appeal to an international audience who think the UK is like... quaint and shabby and old-worldy.
You know what actually captures what living in Britain in the 90s was like? Derry Girls. It's Northern Ireland, but watching that first season was like "Yes. This is exactly what it was like in Northern England back then."
I was actually impressed by how the Netflix adaptation of Heartstopper is relatively accurate to modern, multicultural Britain. I really kind of thought they would do something like that weird "Sex Education" show where everyone's nominally British, but their school and their lives seem way more American than anything. Heartstopper gets a pass. It's very southern English feeling, but it feels pretty authentic to modern day Southern England.
Weird one, but Wallace and Gromit is 100% Preston, Lancashire down to the bone. Nick Park is from Preston, my Grandad was his maths teacher in school. There are a ton of really fun nods to Preston, like the evil Cyber Dog in the third film literally being called Preston, or the museum heist in The Wrong Trousers being done on a building you can recognise as the Harris Museum (and appropriately, when I was about eight, I was lucky enough to take part in an animation workshop with Nick Park in that very building!). Plus in one of the shorts released, Wallace invents the "Preston North End Soccer-matic" which my dad absolutely loved (being from Preston, of course he supports PNE!). Wallace's personality always reminds me of my dad, and even Gromit's silent, passive-aggressive suffering feels so Northern English in its own way.
Attack the Block is amazing. Oh my god. What a great movie. I don't know what else to say about Attack the Block other than that film rules and is really underrated. That is 100% London.