Best demonic possessions in fiction

Now this might seem a trivial matter but consider what demons are supposed to be and how hard it is to create a believable possession scene. An by believable I mean as far as is acceptable with the suspension of disbelief re religion that atheists must use and the suspension of disbelief that anyone following the story must use. Both are the ultimate critics of a possession scene in fiction.
I would like to point out though, that if a believable scene isn't possible then you should go straight for the outlandish and never look back.

So here are some of the best that I know of:

Must be added as the character Rafi, who's possessed, is written extraordinarily well. He's strong, manipulative, torturous, has a split personality between original owner and possessor, heals quickly, is gross and incredibly dark. Oh, and imprisoned in a nuthouse where he still manages to wreak havoc. I would really love to see these books made into movies or comics because Rafi just needs to be seen. 

The Exocist

A Nightmare on Elm Street 2 (hesitantly added as Freddy is classed as a nightmare rather than a demon but then, demons are out nightmares)

Onibaba

The Exorcism of Emily Rose

Futurama (hesitantly added as this is a were-car but it is also demonic in nature. Perfect example of make it outlandish)

Evil Dead and Evil Dead 2

Ghost Busters (And back to outlandish)

Morgan Kingsley's continued possession throughout the Morgan Kingsley series by Jenna Black.