I'm not enough of a horror movie connoisseur to list by decade, but here are some random categories from me:

Best Scary Movie: Alien

Best Horror Satire/Deconstruction: The Cabin in the Woods

Best Dumb Horror Movie: Final Destination 4

Best Horror-Comedy: Tremors

Scariest jumpscare in a non-horror film: the sea leopard from 8-below

Shit that still has me a little fucked up to this day: The Ring

Shit that fucked me up as a kid: The Basilisk's voices from HP:Chamber of Secrets, The tunnel in Willy Wonka and the Chocolate Factory, The Worms eating people in the Jack Black King Kong movie, The Balrog

Scariest Game I've Ever Played: F.E.A.R.