Earth/fire, earth/elec seem like it wouldn't know what to do once it controlled 8-man spawns (lol, kill one by one), but fire knows exactly what to do, burn them all down to the ground. 
sounds good grav/ice just doesnt get the job done
all I know is money $ $
Earth/fire is great fun, especially if you like large teams. Lots of AoE mezz and good AoE attacks to boot. Took it a bit longer to really feel mature for me solo, but by the mid-20s, it was cruising right along. It's still one of the few 50s I have that solos fast enough to keep me interested.
Having Vengeance and Fallout slotted for recharge means never having to say you're sorry.
I currently have a grav/ice dominator but his play is very mediocre. I have been told to reroll by people many time but now I am starting to listen. Would Earth/Fire be a good alternative dominator to play? I want to play something that can hold but still dish out major Damage. I also have been looking at Earth/Elec which looks nice too. Any suggestions would be great.
Thanks Catalysis
all I know is money $ $