[Miss Olivia]

Oh man, I have a LOT.
The scene in Alien where the the monster is full grown and pops through the guys skull with his toothy tongue.

The Blob (remake) where Meg comes in the office to see her date covered in goo and being dissolved. (I had a nightmare tied to this last night, actually.)

The Day of the Triffids where the triffid sneaks up on the greenhouse guard....those squishy feet get me freaked out to this day.

The Thing where the dogs get dissolved by the dog alien.

From Beyond where the guy got his hair sucked off by the tube worm, and then the scene where the cop gets eaten by the bugs.

The Ice Pirates, the space herpe. I know it's not scary, but it freaked me out when I was a kid.

I almost forgot the plane scene in The Twilight Zone movie. The part where he jerks the shade up and the thing is pressed up to the glass almost made me pee myself, and the cartoon monsters in the Anthony short scared me pretty badly too.