This is probably the 6th or 7th 100 list we've got running right now, but I wanted to post this before I forgot it. Basically just moments in movies where you were either shocked, repulsed, or just flat out awe struck trying to process what you had just seen. Usual list rules apply. Try to list the movie your scene takes place in too, in case not everyone has seen the flick you're referring to.
No.1 - Suzanne's Lipstick Hungry Ta-ta (Night of the Demons) - Sadly there's no way to post a clip or screen shot of the actual scene mentioned b/c it's got nekkid boobage in it, but a demonically possessed Linnea Quigley runs lipstick over her face and chest... before her boob eats the lipstick tube!
No.1 - Lipstick eating demon boob (Night of the Demons)
No.2 - Angela's big reveal (Sleepaway Camp)
No.3 - Hammer shot to Kirk's head/Pam in the bone room (Texas Chainsaw Massacre)
No.4 - Music composition/Random crap montage (Hard Rock Zombies)
No.5 - Post-drugging blue nightlight scene (Murder On the Orient Express)
No.6 - Kung-Fu albino "PANCAKES!" (Cabin Fever)
No.7 - The wedding dream sequence (Glen or Glenda)
No.8 - Everything in El Topo (El Topo)
No.9 - Travis Bickle's swan song (Taxi Driver)
No.10 - The maggot scene (Galaxy of Terror)
No.11 - The whipping death scene (High Plains Drifter)
No.12 - The "disappearing body in the road" scene (I Married A Monster From Outer Space)
No.13 - Jason makes his first appearance (Friday the 13th)
No.14 - The "belly of the Star Destroyer" opening (Star Wars IV: A New Hope)
No.15 - The Star Child (2001: A Space Odyssey)
No.16 - Killer intestines (Re-Animator)
No.17 - Templar rape initiation (The New Barbarians)
No.18 - Ben's final fate (Night of the Living Dead)
No.19 - Killing of the 8 Russian mobsters (Boondock Saints)
No.20 - Anthony Piana's push-broom (War of the Worlds - Timothy Hines version)
No.21 - "Hand from the rubble" epilogue (Carrie)
No.22 - Final scene of Germany Year Zero (Germany Year Zero)
No.23 - Final scene of Session 9 (Session 9)
No.24 - Unmasking of the Phantom (Phantom of the Opera - 1925)
No.25 - The shower murder (Psycho)
No.26 - Carl Maitland realizes he's dead in "Reflection of Death" (Tales From the Crypt)
No.27 - Surprise sewer opening segment (A Name for Evil)
No.28 - Solder belly wine dispenser (Caligula)
No.29 - Lionel's lawnmower bloodbath (Dead Alive)