My favourite horror/thriller scene is in Dario Argento's Profondo Rosso --->

http://www.italica.rai.it/cinema/film/profondo_rosso/foto1.htm

 You can see a patchwork of best scenes here:

http://www.youtube.com/watch?v=LtzgOfrRbhs&mode=related&search=

Look and then tell me what do you think about it....The film is dated 1975! Maybe the final scene in which the killer is decapitated by the elevator is one of best horror/thriller scenes ever...

Sonia

Strangely perhaps, one of my favorite scenes ever in a horror movie came from the schlocky Lair of the White Worm.  It was pure shock value scene, where they discover someone has fangs, but it scared the crap out of me.

I also really like the scene in the car from the original Phantasm film.  So creepy and good.

-cg

One scene that stuck with me is the one from Petsemitary I, where the baby cuts through the...what do u call it now...Achilles' tendon maybe? Anyway he cuts through a heel with a scalpel. I just shiver all over! might be cause i saw it in my early teens and got really nauseous then.