I've seen a whole load of screamers, so let's begin.
Jay Leno had multiple screamers (made a thread about this once.)
A YouTube video "Scary Baby,"
The ghost car,
The difference between two rooms,
The rocking chair,
The seductive girl (thanks again, Leno.)
The Christmas song one,
This flash cartoon called "Father Christmas" on Newgrounds,
The classic scary maze game,
Jeff the Killer,
This one of a scrolling forrest panorama,
A "Where's Waldo?" screamer,
One where you stare at specific dots,
And one of this girl on a bicycle.
I never scream, I will just jolt around and I used to cry a lot afterward, now I just jolt, sometimes go like "Oh God." or make a weird noise, and my heart races.