Zangarmarsh. I know it's not vanilla but if I think of one zone where I always completed every single quest, it's Zangarmarsh. It's effortless and it was always so pleasant to quest there. When retail decides to shut down for good, that is where I will be parking all of my retail toons to reside for infinity.
Nostalgia wants me to say Dun Morogh.
I honestly dont think i have a favorite because there were alot of zones i liked
For some reason i really like the Wetlands, but top of the list would be Hillsbrad, Arathi, Redridge and Duskwood!
The Burning Crusade is coming soon
Nobody the grandness of Feralas!? Worked for me! That and ashenvale.
The Barrens and Stranglethorn Vale.
Nostalgia and overall feeling of these zones are just perfect!
Leveling, I like Westfall
Leveling Mining, I like Un'Goro (just go round & round)
Leveling Herbs, I like Swamp of Sorrows (herbs everywhere)
Leveling Skinning, I like Stranglethorn Vale (Nesigwary camp)
Nevermind, just change all that to Stranglethorn Vale, yep.
I can't really say since i haven't been to every zone in classic wow. If i were to guess, i'd say either STV, Hinterlands, Winterspring, 1K needles or blasted lands. I think every zone looks amazing lol.
No original unarmored epic mounts
For me there are a few zones that come to mind: Teldrassil and Ashenvale have that magic forest vibe going on and Un'Goro has the untamed wilds atmosphere. But I like Feralas just as much. So for me mostly zones with lots of foilage and trees. I mostly dislike the barren zones like Tanaris, Blasted Lands or Silithus.
To conclude I would say that my most favourite zone overall would be Ashenvale.
Duskwood and Redridge.
The entire theory behind picking different cholor schemes mentioned by Blizz is pretty clever and definitely had an effect on me. (Going from Green to Yellow to Red to Blue, if you play a Human) That's part of the reason I never liked questing in Kalimdor as much. Just a lot of deserts, mountains and wastelands there imo.
Redridge gives off that cozy atmosphere of your average (in a good way) RPG town, and Duskwood has that spooky vibe, great quests and memorable moments and they both have very fitting music.