By popular demand (okay more like a tiny amount of chatter led by a Brit with an alligator obsession - just kidding Suze!), I present the latest top ten list, The Top Ten Supernatural Antagonists. 
I hestiate to call them villains, because this show prides itself on blurring that fine line between good and evil. These sometimes ambiguous often deliberate baddies (or nasties as some call them) fall into one of three categories. First there's the faceless ghosts, spirits and other creatures that are more scary behind the scenes doing their bidding than when they actually surface. You know, the ones we could care less about. 
Second are "the big bads," aka the ones that surface multiple times with the main purpose of wreaking havoc on the Winchester mission statement. Those will have a presence. 
Then there's a smaller third category, which involves those interesting characters making one time appearances that actually make villainy fun. They also have made this list, but it’s stunning to see how few there are out of 82 episodes. Also after shuffling through the possibilities, one surprise made the list, ranking pretty high. I'm sure you'll know it when you see it. 
As a bonus, I'll also present a top five worst villains list. That list was actually much harder, because there were so many candidates. 
So, without further adieu, I start with the honorable mention and #10. 
Honorable Mention - Racist Truck
I know, this could easily be #1 on the worst villains list. I decided though that the truck's owner belongs on that list instead. The racist truck still inspires the masses to go "Seriously Kripke?" but at the same time, Dean's final altercation with that truck is one of our biggest guilty pleasures. Why don't we watch that clip, and they shyly slink away with a smile, never to speak of such ridiculously villanry again. That is until we come up with the "What was Kripke thinking?" list. 


#10 - Siren
Siren's in lore are supposed to be hot women, designed to lure horny sailors to their doom with their song. Sirens are supposed to take the form of strippers with Disney princess names and entice stupid men into killing their wives with meat tenderizers, right?

Wrong! First, we learn that the siren is one fugly mofo. Then, in a brilliant twist, the perfectly innocent and likeable FBI agent Nick Munroe, who even had the balls to ask for proof that Sam and Dean were legit FBI agents even though he was fake himself, teaches us something about sirens the legends never covered. They really prey on one's deepest desires. As soon as the "in the form of a knock 'em dead gorgeous woman" siren figured out Dean's deepest need, all of a sudden she becomes the brother he always wanted, and not some "bitch in a g-string." 

Dean easily falls, and in devastating fashion is forced to see in a very warped way Sam's true colors, something that lingered beyond this episode. Ditto for Sam, who was a little more willing to brush Dean's slight under the rug to cover his own guilt over calling his brother weak and a whiner over his time in Hell. Uh yeah, "boo hoo" delivers a pretty strong message.   All this because a siren got bored. That's one hell of a creative villain. Any creature that twists up the Winchesters so bad that they beat the crap out of one another and have to be saved by Bobby wins with me.