The first Nightmare on Elm St, most especially because of the scene where Tina buys it....she's on the ceiling and blood is everywhere.

I think the true slasher is "Texas Chainsaw Masacre."

Friday the 13th
Halloween
Halloween: H20
$la$her$
Ripper: Letter From Hell
Hell's Highway
Scream
I Know What You Did Last Summer
Urban Legend
Valentine
Pieces

etc...etc...

Scream
Nightmare on Elm St
Cherry Falls
Friday the 13th