I have always favored the Necromancy school (just the non-combat spells though). I particularly like Clone, Animate Dead, and Gentle Repose..
These spells are just so good at portraying the "mad scientist" type character who likes to mess around with what he should not
Animate Dead and all its variants are useful for making insane (or "exccentric") necromancers who animate the dead for weird purposes, like if a necromancer is so delusional he believes the undead he creates are really brought back to life.
Necromancer: Say, Aunt Edna, you sure are quiet tonight.
Zombie: Uuugghhh...
Necromancer: You sure tell the funniest stories...
You can portray these necromancers as evil, humorous, or tragic.
I like Clone because it always gives the players fear that the necromancer they killed will just come backfrom the deep sleep once again.
For similar reasons, I like Create Crawling Claw, Bogun, Unseen Servant, Simulacrum, Minor and Major Creation[/I] , because they allow you to create things instead of destroying them.
I also like Continual Flame as the spell that lets you create the easiest magical item.