Eh? They're all very useful for a magic aligned character.
Illusion -> Charm, Paralyze, Chameleon, Invisibility (finishing all Oblivion gates in 2 minutes)
Alteration -> Shield, Feather, Open Lock, Water walking, Water breathing, (Levitate)
Mysticism -> Dispel, Soultrap, Reflect spell, Absorb spell, Detect life, Telekinesis