I want to be: Maleficent!
I think the costume would be releatively easy to make. It is described here: Maleficent appears in the form of a tall, green skinned woman with yellow eyes and massive horns, symbolic of her evilness. She is clad in a black and purple robe with bat wing-like edges, and wears a gold ring with a large circular black stone in it. She has a pet raven called Diablo, and a legion of goblins and troll-like entities at her command. In addition to this she carries a staff with a glowing green orb at the tip, through which she casts her spells, which include an ability to teleport herself from place to place or send bolts of lightning at enemies. She is also capable of shape shifting at will into numerous forms, including a will-o-the-wisp and a massive black and purple dragon. Despite this, she is in fact a fairy rather than a sorceress like the other three fairy godmothers in the movie. She is also renowned as being somewhat beautiful in a macabre fashion.
I can't wait!!! What are you going to be for halloween?