I went with Earth/Fire/Ice and like it the best out out of the 3 set out Doms I have (dark/psy & plant/thorns are the others). It feels the strongest in terms of damage output and control of enemies. The dark/Psy has fantastic survivability ala regen/recovery but I rip through mobs so much faster on the earth/fire. I also prefer a mainly ranged Dom. My def isn't even that good with only s/l at softcap but Earth is your main defense anyway. When everything is held/stunned/falling down and immobilized they can't even get a shot off.
I look at it like this, I'm getting all the control I could ever want from my primary and I get my aoe & shields from pools and epics so all I need is strong single target damage from the secondary. This is what fire excels at! So aoe stun > aoe immob > sleet > ice storm and then my single target rotation (single target hold, snipe, blaze) on anything that survives that. Proc up that single target hold, its the strongest attack I have. Consistently stronger than snipe or Blaze, both of which are also very strong. Consume is always handy but I'm on the fence with Firebreath. Its okay damage but its a narrow, sorta short cone and I find I just don't use it very much, I may swap it out for the single target immob as that may have a little more utility.
Anyway, I vote Fire!