I would probably go earth for one of the sick sub-bending techniques like metal bending or lava bending. Plus I think being able to dig tunnels on a whim would be incredibly fun!
I've always said fire because I think it's badass. I think earthbending "looks" the coolest in terms of moves though.
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Yeah, but fire only has that limitation in a certain film we ignore :P
I love fire. It is so versatile, and has the best sub-bending categories.
Which sub-bending techniques in particular? All I can think of is lighting, which is indeed pretty dope.
I tend to go for air. There is air in everything and the ability to use it would give you a hand in all.
Fire is pretty great, but I'm also scared that I would accidentally burn down my house. So I'm going to go with air, since a) there's always air to bend, and b) it has a sick fighting style.