Favorite spell for each level

[Vhaidara]

Pretty self explanatory, but try to stick to core spells.

0: Ray of Frost (most damage, therefore most useful)
1: Magic Missle (reliable damage at lower levels)/Levitate (Damn useful)

[cupkeyk]

Oh no.

(Prepare to be told how bad a school Evoc is)

0- Arcane- Detect Magic
Divine- Purify Food and Water

1- Arcane- a toss up between Colorspray or Silent Image.
Divine- Bless or Entangle

2- Arcane- Tasha's Hideous Laughter or Ray of Stupidity
Divine- uhhh... Blindness/Deafness

To be continued...

[Wraithy]

come on, Prestidigitation is the best spell IN D&D
it makes things... do... stuff.
yeah, I didn't think this through now, did I?

[Crow]

0. Prestidigitation
1. Shield
2. Mirror Image
3. Displacement
4. Stoneskin
5. Teleport
6. Dispel Magic (Greater)
7. Waves of Exhaustion
8. Mind Blank
9. Mordenkainen's Disjunction

[Reinboom]

Awww... just core?

Aside... core:
0. Detect Magic or Prestidigitation
1. Shield
2. Invisibility
3. Haste
4. Invisibility, Greater
5. Teleport
6. Disintergrate (though I take Dispel Magic, Greater before it always... out of need)
7. Limited Wish (for reasons that requires noncore....)
8. Mind Blank
9. Otto's Irresistible Dance

If noncore allowed (list still includes 2 core spells):

Spoiler

Show

0. Launch Bolt
1. Benign Transposition (<3 <3 <3)
2. Phantasmal Assailants
3. Haste (still)
4. Ruin Delvar's Fortune
5. Fly, Mass - unless I have level 6 spells - then Dimensional Shuffle (see my 6th level choice)
6. Anticipate Teleportation, Greater
7. Limited Wish
8. Maddening Whispers
9. Programmed Amnesia - though I will never take it because of power restraints... so... Otto's Irresistible Dance (still).

[CASTLEMIKE]

0 Prestidigitation
1 Color Spray
2 Mirror Image
3 Any Spell (Tried to stick to core but this really is a favorite for a caster)
4 Shadow Conjuration
5 Teleport
6 Any Spelll (Tried to stick to core but this is really a favorite for a caster)
7 Limited Wish
8 Moment of Prescience
9 Miracle (for lower level spell duplication, not crazy magic item creation or freebie expensive spell component spell duplication)

[AKA_Bait]

Core Sorc/Wiz:

0: Prestidigitation
1: Identify
2: Knock
3: Arcane Sight
4: Greater Invisibility
5: Feeblemind
6: Greater Dispel Magic
7: Limited Wish
8: Binding
9: Meteor Swarm

[Sornjss Lichdom]

0. Prestidigitation
1. Silent Image
2. Invisibilty
3. Fireball (it's my favorite not the most useful, useful would have to be nauseating cloud)
4. Diminsional Door
5. Overland Flight
6. Repulsion
7. Finger of Death
8. Horid Wilting
9. (cheese) Time Stop (snap, fireball fireball fireball, cloud kill, and all the doors are now looked. f**k*** Wizard.

[Reinboom]

9. (cheese) Time Stop (snap, fireball fireball fireball, cloud kill, and all the doors are now looked. f**k*** Wizard.

Delayed Blast Fireball* Delayed Blast Fireball* Delayed Blast Fireball*, you mean?
Normal fireball has no effect in a time stop, since:

While the time stop is in effect, other creatures are invulnerable to your attacks and spells

[Chronos]

0: Ray of Frost (most damage, therefore most useful)

Without getting into the issue of damage spells in general, a plain old nonmagical dart is better than a Ray of Frost. And even if we're only looking at spells, an Acid Splash is better than a Ray of Frost, too, since more things are resistant/immune to cold than to acid.

My list:
0: Prestidigitation
1: Silent Image
2: the 3.0 (or even 2nd edition) version of Alter Self (it's way too overpowered in 3.5)
3: Shrink Item
4: Shadow Conjuration
5: Shadow Evocation
6: Greater Heroism, I guess, but none of them are too compelling to me
7: Reverse Gravity, for the huge area-of-effect catgirl kills
8: Telekinetic Sphere
9: Shapechange (yes, it's cheesy, but so is everything at 9th level)