Since i'm a fan of the genre, here's my top 102:
1. Psycho (1960).
2. The Exorcist.
3. The Shining.
4. Dawn of the Dead (1978).
5. Night of the Living Dead (1968).
6. Halloween (1978).
7. Henry: Portrait of a Serial Killer.
8. Rosemary's Baby.
9. Misery.
10. Frankenstein (1931).
11. Nosferatu (1922).
12. Deep Red.
13. Suspiria.
14. House of Wax (1953).
15. Jaws.
16. Bride of Frankenstein.
17. Horror of Dracula (a.k.a. Dracula 1958).
18. The Thing (1982).
19. Silence of the Lambs.
20. Dracula (1931).
21. Friday The 13th (1980).
22. Videodrome.
23. Se7en.
24. Dead Alive (a.k.a. Braindead).
25. Evil Dead 2.
26. Re-Animator.
27. Black Sabbath.
28. The Evil Dead.
29. Freaks (1933).
30. The Hills Have Eyes (2006).
31. The Ring (2002).
32. Ichi The Killer.
33. The Last House on The Left (2009).
34. The Texas Chainsaw Massacre (1974).
35. The Others.
36. Tenebre.
37. Grindhouse.
38. The Wolf Man.
39. An American Werewolf in London.
40. The Devil's Rejects.
41. Black Christmas (1974).
42. The Fly (1986).
43. Scanners.
44. Saw.
45. Halloween 2 (1981). (The new one should be cool)
46. Hellraiser.
47. Phantasm.
48. Final Destination.
49. Demons.
50. Perfect Blue.
51. From Dusk Till Dawn.
52. A Nightmare on Elm Street 3: Dream Warriors.
53. Friday The 13th part 3.
54. Poltergeist.
55. Carrie.
56. Fright Night.
57. The Lost Boys.
58. Cannibal Holocaust.
59. Day of the Dead (1985).
60. Cemetery Man (a.k.a. Dellmaorte Dellamore).
61. Silent Hill.
62. The Blob (1988).
63. The Gate.
64. Night of the Creeps.
65. Dawn of the Dead (2004).
66. Creepshow.
67. The Fog (1980).
68. Jacob's Ladder.
69. Tourist Trap.
70. The Wicker Man (1975).
71. Creature from The Black Lagoon.
72. Land of the Dead.
73. Zombie (a.k.a. Zombi 2).
74. Hellbound: Hellraiser 2.
75. Saw 2.
76. Final Destination 2.,
77. Sleepy Hollow.
78. The Hitcher (1986).
79. City of the Living Dead.
80. House By The Cemetery.
81. Pet Sematary.
82. Halloween H2O: 20 Years Later.
83. The Beyond.
84. Let Sleeping Corpses Lie (a.k.a. Living Dead at The Manchester Morgue).
85. The Haunting (1963).
86. Maniac (1980).
87. The Hills Have Eyes (1977).
88. Puppet Master.
89. Magic.
90. House (1986).
91. Dolls (1987).
92. A Nightmare on Elm Street 4: Dream Master.
93. Friday The 13th part 4: The Final Chapter.
94. The Toxic Avenger.
95. Inside.
96. Carnival of Souls (1963).
97. Friday The 13th part 6: Jason Lives.
98. Freddy's Dead The Final Nightmare.
99. Freddy Vs. Jason.
100. Gremlins.
101. Gremlins 2.
102. The Brood.