I think I may be one of the few people who didn't find the Emerald Graves house creepy at all. It was just, meh, I guess. The frozen temple was better, but my comparison for DA games now is going to be whether it meets or exceeds the creepiness leading up to finding the Broodmother, and neither of those were close.
The haunted house made a distinct impression on me because I initially missed the switch that activates the zombies, so I spent like an hour running in circles inside that house, with the lights flickering on and off on their own (which is something that super creeps me out IRL), reading scrambled notes that put together told this awful story, hearing Cole read the girl's feelings off each room, trying to figure out either what to do or how to leave since I was completely lost... it was pretty rad. Once I found the switch and the enemies came out it destroyed the atmosphere and any sense of dread went out the window with the combat breaking out, but until that point it was a damn scary trip.
The frozen temple is unsettling in a different way, the stillness of everything around you feels
wrong (the falling debris of the collapsing roof frozen mid-air is what trips me the most), and I keep dreading that the enemies will start moving any second even though I know they won't. It's a weird gut feeling that reality is not quite matching what you see, like walking in place with VR glasses and watching the world go by but still knowing you're not actually moving. It's... weird.
The broodmother descent is a different headspace for me. I originally played this quest in a very roleplay-immersed mood, so the feeling of descending deeper and deeper into the Deep Roads with no way out but ahead made me anxious and exausted and claustrophobic, rather than scared. It drove my Warden to strange places in her mind, specially once the implications of Hespith's poem started falling into place... I love that moment for my Warden, it was one of the final places where her mind snapped, but it wasn't such a mood of horror as much as shell shock.
Scary by scary, nothing beats the damn alienage orphanage to me. Aaagh that little girl's rhyme is never letting me sleep again. ;_;