After re-reading For Want of Dispel Magic, I was thinking, what do DF wizards need to bring to the table?
Not want, not desire, not build around, but capital-N need to have in order to do their job?
These are spells that I feel do things that you can't easily do another way.
In no particular order:
Dispel Magic and Counterspell. You need to be able to counter magical effects. If they best you can hope for is "maybe he'll snap out of it" or "maybe the spell will run out" or "let's try putting sunglasses on him" you're probably hosed. You need to be able to counter spell effects.
Mage Sight. Although you can generally spot magic items with just Magery and Per, this is a simple, foolproof way to check for them. Don't depend on "I can spot magic items" to spot all magic, either. "More reliable" is worth one damn point. Spend it.
See Secrets. Yes, the Scout and Thief spot stuff without this. They'll spot everything with it.
Remove Curse. If it's not placed on the "cleric only" list, this is a must-have. Be able to remove lasting, curse-like effects - like Curse or Possession spells.
(Forgot one: Continual Light. For the love of everything that is delving, be able to create a lasting light source.)
Campaign matters, too. Felltower rewards Seek Earth, Scry Gate, and Levitate pretty well. But the few above are one that, when PCs lack them, they lack the ability to usefully do things that only wizards can do. What else is on the "must have" list? Not types - I don't mean "some kind of missile spell" but specific spells.