Me and my friend were talking about this this morning and I just wondered what you guys thought

My dream playing environment would be with patient, funny, witty people (me not being DM preferably as I always get a sore voice), in a large space like a library, empty of all but us, with a large table so that I can keep away from everyone else but also small enough so that people can alter the adventure grid, all lit with warm orange lights and with quiet music in the background while we embark on an adventure in Waterdeep / Icewind Dale / Chult.

A tiny tavern with flickering lanternlight and soft medieval music. A bar, a table, some barrels and whatnot, and my old group from high school. One day, when I finally make a decent salary, I'll have that room in my basement, and we can get together for a game.

Both of these ideas are awesome.

Throwing my players into a country-sized dome that works like the dome from "The Truman's Show". Inside will be literally anything from the D&D world that could be made with technology (monsters are automatons and similar stuff). I will control everything while the players live the game.

Alternatively, and also much, MUCH better: The exact same, but I am a player.

There's a medieval-themed restaurant in NZ within which I've witnessed games played during the closed hours of the restaurant. Watch the first and most recent campaign of Epic NPC D&D (on Viva La Dirt D&D channel) to see what I mean. (The second campaign was a one shot done during lockdown over the Internet and not in that restaurant.) That's what I want as my home-cave (without the cameras and without opening into a public dining area of course). It'd be an escape place for all things creative beyond D&D.

A biodome made for D&D. Inside the biodome there is a warm jungle area, a regular forest area, a icy cold snow tundra area, and a dessert area. There is also a cave which leads into a dungeon type of area. Right outside the biodome, there is a tavern. A rolling table that you could move to each area.

For a more realistic idea. A low lying table, with bean bags or maybe even a kotatsu. A slightly warm area with miniatures and dice splayed out across the table. Drinks, snacks and quiet music. My favorite Dm ever and my friends playing with me, and having fun...

Wait, that's EVEN less realistic...

My living room, or that of one of my friends.

I want a big round wooden table with enough room for  eight people to sit socially distanced and bookshelves on the walls and a huge bucket of dice in the middle of the table and a bar in the back and a little bedroom off to the side if people need to take a break.

a cozy basement, decorated to look like a tavern, with a bookcase door that holds every roleplaying book I own (as well as the mortasheen book when it comes out https://bogleech.com/mortasheen-chrono.htm (creepiness warning)). there'd be a snack bar that holds all kind of tasty chips and drinks, and a hidden trapdoor that leads a darker, creepier tavern inspired by mortasheen, that id allude to, but never explain, so their left wondering what's in the "better tavern". also, the table would have a built-in screen to make maps and the like easier, as well as provide thematic music.
on a side note, if you haven't already, perhaps you should check out mortasheen, in its Cronenberg Pokémon glory! (i case you haven't been clued in, I'm obsessed with mortasheen almost, if not more than, DnD)

A huge room, made to look like a D&D world, with the sky and stuff painted on the walls. And it can change to reflect the current state of the story, and a togglable huge grid area so people can move as their characters (and huge tokens to go with it). And maybe some kind of voice-activated dice-rolling interface. 

a medium sized room with book shelves for the rule books, a functional system for storing characters and a map of the setting on the wall. A wooden table in the center with enough chairs and a table to the side for snacks and stuff. Enough chairs for everyone and a framing system for characters/parties that has there name and accomplishments.

A friend of mine started playing music in his campaigns
It got me really excited cause it felt more immersive

https://musicgrab.me/record-music/download-medieval-music/

I love my group of friends. Their hilarious all the time and are constantly twisting my plots in ways I didn’t expect, even if I expected it somehow. I’m currently dming a campaign called Adventure in the Doge Realm and it’s so fun, I just wish they could be a tiny bit serious at appropriate times.

A trapdoor in an open-air courtyard, leading down to a room with wood paneling on all six walls. A long table with three comfy chairs on either side and a large, intimidating chair at the end. (For the DM, of course, MUAHAHAHAHA) Minifridge w/ snack cabinet across the room. Shelf next to said cabinet filled with every 5e book in written history. Gigantic TV screen behind intimidating chair hooked up to my DM master laptop.

Quote from Goliath7723 >>

A large room, with an imposing DM chair, an interactive 3D map of the game, walls that change color based on in-game weather, with my Monday game players (Best people I know). I would want gemstone dice, and online and paper copies of books. I would also want a projector, and SO MANY MINIATURES!

 Awesome 😊

D&D the way it usually is for me, but there's a giant gourmet buffet just... there 

Quote from ShrimpFriedBryce >>

D&D the way it usually is for me, but there's a giant gourmet buffet just... there 

  Very cool

Long but not too long dark oak table with an integrated battlemap system, slots for tablets or computers, a shelf nearby for books and papers, a separate router for great internet, tall imposing DM chair with spikes, a drawer full of miniatures and maps close at hand, a note-taking robot and a minifrige and classy buffet table.

(All preferably in my house)

(And LOTS of dice, just sitting there)