Bumping this with my top twenty since 2000 so far as it's been over a year since i started this thread. Also to get more recs hopefully because i'm getting into horror again right now. Left out Inland Empire coz i'm not really sure how much i like that until i see it again and also i feel weird classing Lynch films as Horror for some reason:
20.The Others (Alejandro Amenábar, 2001)
19.28 Weeks Later (Juan Carlos Fresnadillo, 2007)
18.Pulse (Kiyoshi Kurosawa, 2001)
17.The Eyes of My Mother (Nicolas Pesce, 2016)
16.Maniac (Franck Khalfoun, 2012)
15.The Devil's Rejects (Rob Zombie, 2005)
14.I Saw The Devil (Kim Jee-woon, 2010)
13.Spring (Justin Benson and Aaron Moorhead, 2014)
12.Tucker & Dale vs Evil (Eli Craig and Morgan Jurgenson, 2010)
11.Lake Mungo (Joel Anderson, 2008)
10.The Babadook (Jennifer Kent, 2014)
09.Detention (Joseph Kahn, 2011)
08.Ginger Snaps (John Fawcett, 2000)
07.The Loved Ones (Sean Byrne, 2009)
06.The Witch (Robert Eggers, 2015)
05.It Follows (David Robert Mitchell, 2014)
04.The House of the Devil (Ti West, 2009)
03.Trick 'r Treat (Michael Daugherty, 2007)
02.The Descent (Neil Marshall, 2005)
01.Let The Right One In (Tomas Alfredson, 2008)