Torn between electric and light, but I'd have to go with light.*
  I could move electrons with it, exciting them to higher shells,
  causing the ability to control electricity as well. I could also
  use it to excite wood to make it burn, or change the perception
  of objects (including myself) to disappear. I could also convert
  matter into energy through excitement of electrons to a fast
  enough speed (so far, light's got the max-speed thing going
  right now.. Having control of light would also give me control
  of magnetism as well and of course colors and invisibility...
  but yeah, I guess I just wanna disappear sometimes :P unless we
  got some neutrinos... I'd really like a neutrino sword.. then I
  could pass through matter entirely undetectably... but that's
  rarely an option in elemental lists. PLUS, I wouldn't be able to
  pick it up! damn. But when playing random roleplay stuff with my
  nephew, when he'd ask, "What elemental do you want?" I usually
  end up choosing Ice, just for the challenge of it and being able
  to put out fire, turn into water... and buy myself some time by
  freezing enemies :P** hehe