I really hate (during campaign play) people just acquiring spells as they level - like they just magically appeared in the spell book? pffft! I'm with you on dragons and car parks full of solid gold coins, but that's just one step too far!
Here's an idea I had for a gonzo campaign I might never run. Each Spell is unique - much like Highlander there can be only one, every magic user that a player creates - starts with one spell (randomly determined, re-rolled if the spell already exist in the world)
The only way to gain more spells is by stealing them from other Wizards. That's it.
Suddenly who has what spells became uber important, their actual acquisition roots for adventure - thanks for the hand out PHB but we make our own fun!
Some spells will be forgotten, if the Magic user dies and doesn't pass them on. Nobody knows them, I'd imagine they can be found on dusty scrolls at the bottom of a Dread Beholder's tomb. Apprentices just became important too. Double Dipper!
Also Happy New Year you Bastards.