But as others have pointed out, some of these crop circles are insanely complex, and the way that the plants weren't broken and any other residue deserves to be investigated. Mythbusters did a very good job of breaking the moon landing myth, so if possible I'd like to see them do the same for crop circles, or at least show how such complex designs could be made.
Why is anyone still discussing this? Crop circles were invented in 1978 by Doug Bower and Dave Chorley, a couple of pranksters (artists?). There are several examples of circles which are declared impossible by someone or other, only for the culprit to come forward with proof of his involvement. For example, Doug and Dave supported their claim by fooling cereologist Pat Delgado.
Look at it this way. We know for a fact that hoaxers are capable of producing extremely complex circles. The existence of aliens or ion plasma vortices has not been verified. So if we see a circle and don't know how it got there, which is the most sensible conclusion? To assume that it's the work of hoaxers, who we know to exist and to be responsible for previous circles? Or to assume it's the work of an unproven entity?
Nice post. Hoaxers of course are the most likely, but they are so complex in design, without knowing the data that has been checked, it is hard to not help but be somewhat curious about the cause and see one created on video.