Most of them, in most of the systems I hate.
I don't want to see D&D go that route. Classes like the Beguiler & War Mage already go too far, IMO.
Most of all, I want the archetype I fell in love with back - the scholar whose sole* source of power is scraps of code ("arcane lore", whatever) gleaned from the remains previous civilizations.
* Barring spell research, of course.