I went to WoW Wiki and basically included anything currently accessible in-game as far as zones go. This is mostly to see what the most popular zone in all of WoW is.
RULES:
You may save THREE zones every hour.
ONE save required to save a zone.
Last THREE zones unsafe are eliminated.
No Alts.
No Rallying.
Save trades okay.
No deleting posts.
THE ZONES:
Cities:
Dalaran
Darnassus
Exodar
Ironforge
Orgrimmar
Shattrath City
Silvermoon City
Stormwind City
Thunder Bluff
Undercity
Eastern Kingdoms:
Arathi Highlands
Badlands
Blasted Lands
Burning Steppes
Cape of Stranglethorn
Deadwind Pass
Dun Morogh
Duskwood
Eastern Plaguelands
Elwynn Forest
Eversong Woods
Ghostlands
Gilneas
Gilneas City
Hillsbrad Foothills
Hinterlands
Loch Modan
Northern Stranglethorn
Redridge Mountains
Ruins of Gilneas
Scarlet Enclave
Searing Gorge
Silverpine Forest
Swamp of Sorrows
Tirisfal Glades
Western Plaguelands
Westfall
Wetlands
Kalimdor:
AhnQiraj: The Fallen Kingdom
Ashenvale
Azshara
Azuremyst Isle
Bloodmyst Isle
Darkshore
Desolace
Durotar
Dustwallow Marsh
Felwood
Feralas
Kezan
Lost Isles
Moonglade
Mulgore
Northern Barrens
Silithus
Southern Barrens
Stonetalon Mountains
Tanaris
Teldrassil
Thousand Needles
UnGoro Crater
Winterspring
Outland:
Blades Edge Mountains
Hellfire Peninsula
Isle of QuelDanas
Nagrand
Netherstorm
Shadowmoon Valley
Terokkar Forest
Zangarmarsh
Northrend:
Borean Tundra
Crystalsong Forest
Dragonblight
Grizzly Hills
Howling Fjord
Hrothgars Landing
Icecrown
Sholazar Basin
Storm Peaks
Wintergrasp
ZulDrak
Cataclysm:
Deepholm
Maelstrom
Molten Front
Mount Hyjal
Tol Barad
Twilight Highlands
Uldum
Vashjir