I don't think OBL will count for much in the long run; he's had a disproportionate impact, sure, but nothing of his political/religious agenda has been advanced. The caliphate is no closer to restoration now than it was a century ago. He has failed to ignite a world war between muslims and everybody else. Were such a war to get rolling, his side would not win. So OBL does not get to go on the list.

Dick Cheney, on the other hand, has created an unprecedented role for the VP, and his impact may be long-lasting. More than any other member of the current administration, he has redefined executive power and privilege. You may disapprove of his actions (and according to polls, the odds are very high you do), but there's no denying his impact.