Yay back to seriousness. :P
EDIT: More names added!
Fire themed levels:
Magma Fury Zone
Volcanic Valley Zone (that sounds too generic...is that already a level?)
Ash Encasement Zone
Vengeance Flame Zone
Ember's Inferno Zone (yeah a Trivium reference, sue me :P)
Charring Oblivion Zone
Searing Onslaught Zone
Cinder Ruins Zone
Charcoal Relic Zone
Vehement Lava Zone
Water Themed:
Aquatic Tempest Zone (TAKEN)
Azure Tranquility Zone
Ocean Upheaval Zone
Bayside Rush Zone
Marine Surge Zone
Crisis Reef Zone
Nautical Coast Zone
Atlantis Aegis Zone
Placid Lake Zone (Seriously, I'm not referencing the movie)
Grass/Forest:
Arboreal Menace Zone
Primeval Forest Zone
Verdant Labyrinth Zone
Silent Grove Zone
Treacherous Copse Zone
Ice:
Glacial Epoch Zone
Frozen Squall Zone
Frost Ferment Zone
Blizzard Tempest Zone (yeah tempest is a SWEET word :P)
Air/Sky:
Celestial Panic Zone
Empyrean Dominion Zone
Troposphere Torrent Zone
Heaven's Sentinel Zone
Aerial Assault Zone
More to come when I get back from my *gasp* hair cut.
(give credit if used I guess...or not, I don't care) Also, anyone else with a level name block, feel free to use these.