Which are the best maps/set pieces of maps?

Hey people. Been a while since I spent a lot of time with the community I'm afraid. So I wanted to start a little thread to see what you guys like.
 

Looking to find out what your favorit map or set piece of a map throughout the entire history of the Doom community is.

If you're a single player fan, which map or piece of a map had the biggest impact on your mind? 

If you're a multiplayer duel type or FFA , which is your favorite multiplayer map throughout the years (don't say Dwango5m1)?

I'm old now, so my brain is shriveled from all the beer. So I think this

For Dueling in Doom2, Judas23_ or Map01. But has there been any else that reached that quality (don't say Dwango5m1 :p)?
For Single player, Aliens TC always held a special place in my heart as it had an early impression on what could be done within Doom's engine.
Batman and Action Doom was impressive for the technical aspects alone, in particular the boat ride made my jaw drop. 
Zan Zan was crazy impressive for it's time as well. 

I can list a lot of technical achiements that has made my memory bank as well such as Phobos: Anomaly Reborn or the top picks in the 10 sector contest.

But I am struggling to think of specific areas of game play that had me floored. And not because I didn't encounter them. But more because I need a reminder.

The most specific case where I can recall enjoying a map or mapset for game play alone would probably be @Jayextee's mapset Murderous Intent.

So which maps was the most important for you?

for modern, but not gameplay-modded gameplay (i.e. vanilla weapons/enemies), NEIS e1m9 by @NaturalTvventy springs to mind, as well as cchest4 map06 by @Capellan

Sunlust map29 archvile carousel.

I'll definitely check those out. Care to explain what it is you guys find special about them?

4 hours ago, kristus said:

I'll definitely check those out. Care to explain what it is you guys find special about them?

When you see it you'll understand immediately. 

Sunlust MAP29 has a room with a cluster of archviles stuck on a central island, encircled by a ring of lifts, which rise in waves rotating around the archviles. You have to match speed with the wave cycle to stay out of their sight.

Decino explains the room around 8:00

On 8/16/2021 at 3:07 AM, Jacek Bourne said:

Sunlust map29 archvile carousel.

OMG

I don't really feel like listing tons of difficult maps but since I pretty much only play difficult maps these days so lol.

Miasma - A really big map contains lots of secrets. This map really feels like a adventure for me though some fights might be too harsh. You'll surely like it if you're a secret hunter.

Twilight Massacre(SOD map 28) - I list this map not because it's unique and difficult, but rather the most relaxing and fun slaughter map I've ever met.(Also easy if you know how to use BFG properly) I often replay this map just to relax.

Ocean city zone act 2 by super sonic doom