I don't have any specific spells that I particularly want to see. But what I want to see are:

1) Spells that draw from multiple schools of magic. Quite frankly I think dividing spells up into mutually exclusive schools is limiting and simple, and there are so many ways of combining them to result in more variation and complexity.

2) Contextual spells whose effects vary based on the context in which they're used. For example, a freezing spell that can be used to freeze a river, making it impassable to boats but crossable by ground troops; or they can freeze crops, destroying them; or to freeze enemy troops during combat.

I like the basics.  You know, classic staples of prestidigitation, such as:

Fireball

Magic Missle

Mordenkainen's Illustrious Illusion of Effluvium (a.k.a. "Shit Storm")

My favorite spells from MOM (which haven't been mentioned in the OP) were Time Stop and that "raise zombies everywhere spell" which IIRC Armagendon(?)

Timestop was awesome game winner spell what would happen is you cast Time stop and only you can make moves, oppenents you attack can fight back but they may not move on the main map. In addition nobody produced food, products, research or Mana. And cost you a shed load of mana a turn (i think about 35). Anywho it was such an Awesome spell.

The zombie creater spell was even cooler basically every fight you won you got zombies back from the dead (from your fallen commrades) and in addition hostile zombie mobs spawned throughout everybody else's land.

I really like the sound of the contextual spells like the freezing river. Though I think I would prefer being able to use fireballs to kill soilders/peasent, burn down vilages (targeting buildings), crops and perhaps melting galaciers or evapotaing water sources.

As for creating diseases that would be cool and from a gameplay design point of veiw, having them affect species(or even better individual subgroups within them, so that I as a human could create a disease to kill other humans whilst being immune to it) does make the most sense. Its not strictly speaking true it would depend upon each individual disease and its source (whether that be virus (most specific) or Bacteria (much less specific). And on top of that with them both the Human and the Fallen being very closesly related its hard to imagine that they be affected by a competely differnt set of diseases.

*But i think a super complex disease models working around pathogensisty factors vs Host defence factor, taking into account the individual condition (both poir and throughout the disease), modes of transmittion, evolution and resoivour of infections. Would be beyond the scope of this game. And i'm bretty sure if somebody could generate a model taking into account these type of factors you'd probably find it indemand from numerous scientific intestutions and a bit too complicated for Elementals target audeince (no offence).

Any takers?

I like a lot of the sorcery spells from MoM, like confusion, psychic blast, phantom warriors, counter magic and such.  It'd be really awesome to see some nice meta-magic spells that alter your enemies spells, or your own I spose...  say, the enemy casts something like wrack, and then you cast a meta-magic spell on his wrack spell that refocuses it back on his own troops, or turn it into a healing spell for your troops or somesuch..

I really like chaos channels too, the fact that it's both random and permanent.

I also wanna see some epic world-shaking spells like armageddon and zombie mastery.  There better be some sweet necromancy...

And flying cities of course!  thank you for the awesome pic Luckmann

summon Torin the Chosen One

http://www.masterofmagic.info/Document/torin.php

Spells that give you information about the other empires; I would like to see a more intricate mechanism than for example Master of Magic where you just had to bring a unit within range of an enemy's city to see the military units defending the city. The same with those graphs we're so used to where we can track our economical, military, research and other progress versus other empires: while it's very useful information it's a bit too easy, so let's see some crystal ball spells

Which reminds me of Utopia's crystal ball application, so I'd like to see some divining spells that give you an idea of the likely outcome of a potential battle: you cast the spell, indicate your troops and the enemy's and get a rough idea of what the outcome could be like.

Summon Cthulhu: expensive spell that requires human sacrifice but every few turns will cause some villagers or lower military from other empires to desert to your side

Wall of Stone? 

All that one did was give you a city wall.  You could build one for like 50 RPs.

I needed crusade for champion slingers.  (took out 9 skydrakes without them getting a hit in)

I also liked black channels with ultra elete war trolls casue they stoped costing food and money and I could darkness to give them even more swords and armor, and if they were hurt or died, they regenerated at the end of battle anyway!

Then, stream of life on all my dwaven cities, bump up the taxes to max, cast the +50 percent gold enchantment and + 50 percent work bonus ,and then switch to trade goods.

over 7000 gold per turn!  So much gold that the counter reset (went from 30 somthing thousdand to 0).  Sad part was, there was really nothing to buy cause I was so developed anyway. 

God I love this game.

AoW classic - Hell fire (I think that is what it was called.  Fire rained from the sky onto a city.  It did a ton of damage and was fun to watch)

MoM classic - Armageddon

MoM classic - Just cause (except I of course would want it to do more in relation to diplomacy.  If this was exactly like civ 4, which I know its not but its my best starting point, I'd want it to give +1 relations with all other wizards, and have that slowly go up over time that the spell is in effect.)

In Dominions 3, you had a spell called 'Wish'

Basically, the spell allowed a very very experienced caster to wish for something. You could type the thing you wish, and you get it. Immortality? Sure. A huge army standing in front of your castle? Hah, the fools, wish for reinforcements and you'll be granted hundreds of men. Low on resources? No problem. I just loved the freedom that spell gave you.

I basically let my pretender god (the experienced caster) sit in a corner of the map, mumbling wishes until my opponent took over the whole world apart from my little spot and basically became too strong and the Wish spell became to expensive to cast and I was thrown into the void Still, sitting for about an hour, only watching the effects a spell gave you is impressive and I wish (no pun intended ) for a spell like that in Elemental.

uh... I know...  I was talking about a spell that was in MoM in the first place...  "Just cause" which was in MoM... They both were supposed to better your relations with enemy wizards, I felt that just cause was better (in name and function as it also made better heros and mercenaries appear as well).

When I was a kid I loved "Just cause" because I did not read it as "a cause for justice" but rather as "just because".   A spell that betters your relations with everybody and raises chances of you getting better offers from the random AI then naming the spell "just 'cause" was the coolest thing to me.  "Why do they love you?    just 'cause  " Now that I am wiser, and my vocabulary is better versed, and I realize that if it was "just because" then there would be an apostrophie to mark the slur over 'be', I know now it isn't as cool.  But I still like the spel. 

Just cause seemed to have done both.  its description was in bettered relationships AND helped with heroes and magic item sales.  The spell itself did that by gaving you extra fame (which effects hero/unit recruitment).  Aura of Majesty might have been better for only relationships, but "just cause" definatly did everything.     I would cast just cause and all the wizards would pretty much now love me.  (or hate me less)

now that I think about it, fame itself might have just directly affected relationships, which is why "just cause" did it.  So maybe my example was bad.  It wouldn't be +1 from the spell, but rather +1 form "this guy is renown for his goodly nature".  But that leads into the AI diplomacy and honor discussion, which is a different thread

perhaps they should be different spells.   Lets throw aura of magesty on the pile of desired spells.

A wish spell would truly be awesome! Actually, it would be sweet if you typed in "I want lego" and a lego appeared in your main city.