suggest some good thriller to watch in a group!

I am looking for some good thriller horror movies to watch with my hostel roommates.!
we have watched movies
1: orphan (we all loved it)
2: shining (again loved it)
3: excorcist (didnt like it very much partly because we thought it will be very horror but not)
4: sanctum (my roommates like it i was pawning all the time)
5: little liss sunshine: I loved it they were yawning though. lol
we watched other movies as well like the rite, 30 days later, (some vamp movie i might even naming wrong but we all disliked it) so to give you an idea of our taste.
we all hate gore in between!
:)
we have watched movies
1: orphan (we all loved it)
2: shining (again loved it)
3: excorcist (didnt like it very much partly because we thought it will be very horror but not)
4: sanctum (my roommates like it i was pawning all the time)
5: little liss sunshine: I loved it they were yawning though. lol
we watched other movies as well like the rite, 30 days later, (some vamp movie i might even naming wrong but we all disliked it) so to give you an idea of our taste.
we all hate gore in between!
:)

Yep, I'd agree with The Sixth Sense. Also, Jacob's Ladder, Silence of the Lambs, The Ring, The Others, The Orphanage, Stir of Echos. None of them are particularily gory, but all are pretty high on suspense in different ways.