This post was from a user who has deleted their account.
Personal favorites of mine were Hellfire Peninsula, Netherstorm and Borean Tundra. Back when I first picked up the game in the later half of BC, just after Zul'Aman released to the public, I didn't expect Outland to be anything like I was assuming it'd be. After my initial first 58 levels or so in the rather down-to-earth Azeroth, I was hoping for something a little more exciting to take in. The most bizarre thing I ran into during my Azerothian escapades was Un'goro Crater, with all the slightly out-of-place dinosaurs and the omnipresent Ninjasaur that seemed to tread on you when you least expected it. I was excited to see Outland for the first time, and I was still blown away by the first sights of the Dark Portal and the battle at the Stair of Destiny just on the other side. I was just expecting the old "Wal-Mart greeting" zone entrance of "Welcome to Outland, do your quests and get out.". Instead, I was caught in a battle for the Portal entrance and then aiding the Horde war effort taking on all these alien lifeforms like Flayers and the demonic Fel Orcs. Also seeing the incredible sky view of Hellfire was a treat, it looked like something that should've graced a Pink Floyd album cover with all the color it used. Netherstorm was a little different in terms of seeing it for the first time, seeing what Outland's damage really was after Gul'dan's failed experiment. I didn't fathom anyone would be ballsy enough to stay in Netherstorm, but lo and behold, there was tons of life still clinging on to whatever didn't get flung out into the Nether. Borean Tundra was another great expansion introduction for me as well. Both Outland and Northrend's intro zones showed that the Alliance and Horde weren't all-powerful forces that could break down any force coming their way. Instead, they had enemies breathing down their necks and knocking on their doors. Both definitely portrayed a great sense of urgency to me that the Burning Legion or the Scourge weren't to be messed around with. Sure, there was still the typical "Kill 10 critters" or "Gimme 15 bear asses" quest in there somewhere, but the introductory story chains definitely breathed some life into those zones and kept me hooked for the first couple times I ran through there.Don't get me wrong, the new Cataclysm zones were great, but I think that BC and Wrath did the opening 2-3 levels of content the best. Though I do admit I enjoyed the crap out of Uldum and the Mega-Katamari quest.
Personally, I would have to say Teldrassil. Was where i started my very first character, and still one of the starter zones I can go to repeatedly without getting tired of it.
My favorite zone would have to be Netherstorm in Outlands, the huge machines sucking mana power from the sky itself is just breath taking.
Duskwood, no question! The music has a relaxing, yet spooky feeling to it. The scenery is gorgeous, especially for horde ; ) Only thing I don't like about it is the big tree in the middle that you can't fly over.
I gotta say my favorite zone is actually a zone combination. I like Azshara post-cataclysm, and Durotar. I am from the desert so I do enjoy the aesthetic appeal of Durotar, and I love the questing in Azshara, but the thing that takes the cake is that this zone combo is also responsible for Kalimdor's amazing transformation into a chicken. Seriously, if you haven't noticed it, go look. It's amazing. Thank you so much to the goblin race.
Searing Gorge -- when first starting 6 years ago and at low levels it was always awesome to take the flight from Ironforge to Stormwind to check it out, sort of like a little Mordor, I couldn't wait to finally get there. The gorge and the quest down there were really cool, didn't even mind the farming for Thorium Brotherhood rep (then again time might have smoothed out those memories)
I always loved Grizzly Hills. Fo' Grizzle My Shizzle is so me, too!Being out in the wilderness, dealing with Worgen, giant bears, dwarves...greenery everywhere. I loved it!
My favorite zone is Nagrand. I love the floating islands and the scenery of the area. I often find myself going to Nagrand when I have time and just sit on one of the islands and looking out into the distance. I also love Halaa in the area. My server is still very back and forth with capturing the area and it's as if burning Crusade were still the newest expansion.
I'm going with Nagrand as some other people have chosen. The quest chains were great (ie, easy experience!); I always look forward to that specific zone when leveling a new character. It's the prettiest place in the Outland, and it shows the humble beginnings of several characters that become important to the core story later in the game (Saurfang the Younger, Garrosh).
Storm Peaks. I love absolutely everything about the zone. I love mountains and snow in real life as I'm an avid snowboarder, so the moment I saw Storm Peaks, I felt like I was home. Then I heard the music and it sent chills down my spine. I loved the entire Sons of Hodir quest chain and I'm still convinced The Drakkensryd is the best quest ever. Not only that, I love all the Titan stuff in the zone, and my favorite raid ever, Ulduar is there. I still like going back to that zone to fly through.
I still love Black Temple. I absolutely love how you progress from the sewers below the temple, all the way to the top of the temple. Doesn't hurt that Illidan Stormrage is found there either. =P
Lorewise I've always loved the Plaguelands (both Eastern & Western) For me they've always been the scene of many awesome battles, and have some of the most heart breaking quests. (Pamela's Doll anyone?)
Mine is Nagrand, great memories of farming there for any tradeskill.
Tranquillien, bar none. The atmosphere, the quests, everything captures the feel of the Blood Elves reclaiming their lands after Arthas and the Scourge razed it, up to the gates of Silvermoon. Mopping up the last of the Scourge forces and eventually making your way to the Undercity to see Sylvanas and to Orgrimmar to pledge your allegiance to Thrall was absolutely epic.
My favorite zone is Durotar, because the story behind its name and the building of Orgrimmar is really good.