Agree that LeMay is more of a “potentially worst military leader, but it never happened” if you’re talking about a global nuclear exchange, and “just another ruthless bastard” if you’re talking about the strategic bombing of Japan’s cities.
I don’t understand why people are moved to vote Goering off so soon.  Although we consider him a buffoon, he was actually a decorated officer and the Nazis put him  in charge.
He promised he’d destroy the RAF in the Battle of Britain and then managed to lose through a combination of:
[ul]
[li]simply not putting much effort into thinking about how to do it[/li][li]failing to understand the new technology of radar[/li][li]failing to adapt to the unexpectedly well-coordinated RAF response[/li][li]repeated, ill-timed meddling in the targeting priorities[/li][li]believing uncritically in wildly overoptimistic claims by his pilots (despite his own WWI experience with pilot claims)[/li][/ul]
At one point the Germans had fought roughly equal numbers of RAF aircraft on their previous mission, yet somehow Goering was persuaded that intelligence analysts now thought that Britain was down to only 40 operational fighters.  Maybe he thought the 700+ he’d faced only the day before were all being repainted?
One hallmark of a truly bad military leader is when they draw the wrong lesson from real-world experience.  The big lesson Goering drew from the Battle of Britain was that the British wouldn’t “come up and fight,” facing the Luftwaffe in battle so that their fighter strength could be destroyed.  This was after he’d decided to stop attacking their bases (which had in fact almost worked before he prematurely called it off in favor of ineffective savagery against civilians) edit:  and which could be characterized as “going down to fight them where you find them,” thus being equivalent to what he complained they were too afraid to do.  Rightly or wrongly, Goering was certain in his own mind that a numerically inferior fighter force that came up to face escorted bombers could be destroyed, opening its homeland to invasion.
So what was his response to Allied bombing?  He sent his numerically inferior Luftwaffe up to “fight it out,” where it was indeed destroyed, opening his homeland to invasion, exactly as his own theory predicted.
Maybe not the worst ever, but I say he should stay on the list until after we’ve booted off the non-losers and accident victims, at least.  And maybe also the massacre guys…Goering ordered bombing of civilians and lost big-time.
Plus, I enjoyed calling him “prancing.”
And McClernand should go off the list before Butler, when you’re booting Union political generals.
Still concerned I don’t know enough about some of these guys.
My votes:
George Tryon - 2
Curtis LeMay - 2
John McClernand - 1
.