There's just 4 (5) that I'm using.

Arcane Barrage
Cone of Cold
Arcane Explosion
Fire Blast

Then at 63 I was also using
PoM-Fireball
and at 64
PoM-ArcaneBlast

Being Arcane speced, Presence of Mind has only a 1.4 minute cooldown.
And I also have Arcane Power (+20% dmg for +20% mana cost) tied into my Arcane Barrage macro. That's also on 1.4 min cooldown.