Pay no attention to all the silly replies above me. *(just teasing)
The obvious answer is/are:
1. The Betty and Barney Hill alleged abduction. It contains some aspects that few other cases have. For one thing, if true as stated, it would
document the first link between an alien being, an abduction and a non-terrestrial craft flown by said alien(s).
2. The Lonnie Zamora case. It also would document an actual craft in operation (and not a mock up) with live beings. If the 'witnessing' was allowed
to be infinite zoom and pan, one could identify details. One could also see how the interaction damaged Zamora's car.
Though some might pick the Roswell case I think that it, as stated contains significant flaws as a 'best case' to witness.
In the two cases above, we reportedly would see the craft fly, land, and take off again. One could also 'board' the craft and virtually look around.
The Roswell craft, usually depicted with -dead- aliens and a crashed craft would not give up significant detail to identify it as real without an
autopsy and extensive testing of the 'dead' creatures to assure their non-terrestrial origin, and according to the thread, we would not have the
opportunity or means to do that. It would be impossible through normal 'witnessing' to prove the 'craft' could fly, or that the 'dead aliens'
were non-terrestrial and not just convincing dummies with a craft mocked up, perhaps for training purposes?
In addition there would be no way to ascertain that the 'crashed craft' was ever able to fly, was truly non-terrestrial in origin (just by
witnessing, iow), and no real evidence that the aliens actually used that craft. All that would be non-supported deduction and inference, unlike
(presumably) the Hill case where we'd -see- the craft flying and landing and taking off, and see the aliens disembark, and we'd see them interacting
with, and possibly examining and paralyzing the Hills. We'd also get to see their gear.
(Obviously if the Hill case ended up being a fabrication, in whole or part, then the Roswell case with (presumably) actual artifacts (proven ET or
not), which are better than a hallucination, obviously, if the Hill case would turn out to be so, then it would move to the top spot.)
Another reason the B&BH case would be the top pick is that it may contain the link between any EBE and the US military. There's some evidence that
the military did track this event but know more than they are disclosing.
Great question, btw.
[edit on 17-3-2008 by Badge01]