1) Haste
2) Reconstruct (anyone without this on a Sorc, WF or fleshy, does not deserve a raid slot, scrolls don't cut it beyond normal VoD)
3) Wall of Fire (the absolute pinnacle of damage-per-mana efficiency on 80% of foes in the game)
although at present, I'd push Waves of Exhaustion up to #2 on this list.