I'd pick ice. Even if I didn't get to choose, I'd probably get it anyway (what, with being split between cold and removed (ice) with an occasional burst of wit and frendliness (snow)).
Plus, let's not forget how effective it is:
V. Electricity: you have pump a ton of volts through ice to melt it.
V. Water: freeze the water. Done.
V. Ground: if there is ANY moisture in the ground at all, I can freeze it and deflect attacks. Also useful for shattering rocks.
V. Fire: I admit, it is a tad bit difficult to block fire with ice, but you can't win everything.
V. Wind: About even. I guess wind could cut through the ice, though.
And, if there is ANY water vapor in your lungs, I can freeze it and cause you to drown in your own blood from the internal bleeding. Thats right.
Oh, yeah, and heroism. It's a lot easier to restrain someone by freezing them than anything else (except maybe burying them to neck height w/ground). Yeah, they get some tissue damage, but that's what they get for being evil.