Lightning I would have Darui's Black panther technique! You can conjure up two panthers and have them fight eachother! The best part about it is that it's not animal cruelty!
Wind, I've always favored the wind and its jutsu seem powerful, and it could be used to extend weapon's range like manipulating shurikens or increasing ranges of swords.
I'd pick earth, since I don't know what other element i'd use to have fun with. But if say we were in a hero/villain type fantasy world, i'd go with lightning. It's fast, and unpredictable. Kills a person in one hit.