Basically title lol
But for me it’s 100% Vol’dun and no not just cause Vulpera although won’t lie thats a part of it 
But I just love the story of the Zone like got Vulpera fighting back against tge Faithless, Exiles fighting to survive in a hostile environment, an inn run by a seemingly mad Troll and can’t forget undead pirates and Cursed Treasure 
Like it can be hard to make a dessert interesting and Vol’dun definitely achieved that.
Anyway what’s your favourite Zone 
Original Ashenvale. Leveling up with the zone theme song and ambiance it was amazing. It was great as a low level NE hunter.
I know you didn’t ask for cities specifically, but probably Ironforge, Dalaran, Stormwind.
Nothing beats the vibe of a busy morning in one of those cities back in the day.
Outside of cities, I love Winterspring and Strangletorn Vale.
Elwynn Forest and SMC.
Ashenvale was my fav in WC3.
In WoW it is the AV battleground. I like it it is very pretty.
Then I like Grizzly Hills for the music
Northern Icecrown.
Changing my vote, how could I forget Suramar? I think Val’sharah is great but man, Suramar is just an S-Tier. A solid raid, iconic as heck dungeon, a great campaign, beautiful BEAUTIFUL zone, the music was great… oh man…
Suramar was so lit.
Always Howling Fjords. The music, the sky, the ambience, the forests, etc.
Grizzly Hills in Northrend. Makes me wish I could have my own log cabin there. Best music of any zone.
Terokkar Forest!
Suramar! One day I hope they will update my precious city to be functional!
Zangarmarsh
Elwynn Forest, Grizzly Hills & Valley of the Four Winds!
Hourable mentions to WoD’s Shadowmoon Valley too and the original Westfall as well.
suramar and valshara . silverpine forest
Probably Feralas…beautiful sunsets at dreamer’s rest, a resort, dire maul, and the extended version of Nightsong in multiple areas of the zone. 
Darnassus and Ashenvale.
I know I am a minority but
Vashj’ir
Ardenweald
Stormsong Valley.
I really miss our farms in pandaria
Early Maw.
There are some beautiful zones out there, the Maw is not one of them.
But no place else gave me the actual feelings I felt when wandering around it early on, when it was strong and we were weak, when the Jailer had his eye on us.
Loved the Maw.
Haven’t really had one in a while. I remember enjoying Arathi Highlands in vanilla. But back then it was the Un’Goro Crater. It was a place of solitude, good quests and the danger of being 1 shot