Who delivered the final blow?

[the phantom]

Perhaps no one delivered a killing blow. Maybe, even after his Ring was cut off, he would not have died had he been left alone.

But Sauron knew that he was injured, his forces were defeated, his Ring was not directly under his control, and that he would soon be "killed", and so chose to leave his physical form before he suffered an actual death blow- a blow that would have left him no choice but to die.

[Bêthberry]

Oh gosh, I saw the poll title and was hoping I could pick--or do a write-in--for Peter Jackson.

[Farael]

Originally Posted by Boromir

However, I think there's other quotes referring to Elendil and Gil-galad as "overthrowing" Sauron.

Well, Gil-Galad and Elendil were the kings and captains of the armies that defeated Sauron's, but Isidur actually defeated Sauron himself. Or well, they all did, but Isidur cut the ring which prompted the escape of Sauron's soul from his body.