For me, it's got to be the Fire element.
In games where I have the choice between those elements I always choose fire.
Fire just always feels the most powerful. I know it can be put out by earth or water but water is for weaklings and earth is just dirt. (I know these are powerful elements but for the case of this argument in just presenting them in a negative light).
Fire is power and it is the element to choose when you need to defeat your enemies. Unless of course they're mermen in Atlantis. Then you would definitely use electricity.