I'm looking for some interesting titles of some haunted house, or ghost themed horror movies to pick up for my brother in-law for Christmas. The usual suspects, The Haunting, Changeling, Frightners, The Ring, The Grudge, i know about.

This is what I have come up with so far, from some threads here:

THE INNOCENTS
THE GHOST BREAKERS
BURNT OFFERINGS
THE GHOUL
SESSION 9

What else is out there that might be creepy?

The most obvious one you didn't mention is The Others since it is better than any of those you listed.

Frailty is also very good and creepy but it deals more with human souls that could be evil.
From imdb: Plot Outline: A man confesses to an FBI agent his family's story of how his religious fanatic father's visions lead to a series of murders to destroy supposed "demons."

The Entity might be something to look at but I haven't seen it so I can't comment. From imdb: Plot Outline: Supposedly based partially on a true story, a woman is tormented and sexually molested by an invisible demon.

I really enjoyed "Below", which is a WWII "haunted submarine" movie from a couple years ago. Very good, fairly low-key ghost story with a very creepy atmosphere, good performances and a nice unfolding plot.

I liked Boo. It's a low budget straight-to-video movie, and there's absolutely nothing original about it. But it's done so well that the movie ends up being really enjoyable.

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There was another good film called The Collingswood Story. This was an ultra-micro budget film. I don't know if you'll be able to find a DVD. I don't think it ever got an official release in the US. But there's a UK DVD.

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If you can play UK DVDs, you'll need to get Ghostwatch. One of the best ghost movies ever made

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The Uninvited (not sure if its on DVD though)
The Legend of Hell House
Poltergeist
The Fog (1980 version ONLY)
Carnival of Souls (1962 version ONLY)
Dark Water
A Stir of Echoes
(assuming The Sixth Sense is too obvious)

If you guys can handle subtitles:

The Kingdom (not the US series -- the Lars von Triers miniseries)
A Tale of Two Sisters
Original versions of Grudge, Ring, Dark Water, Pulse
The Devil's Backbone
Kwaidan
The Eye
Seance
Phone
Into the Mirror

That's just off the top of my head. There's lots of good ghost stories out there.

If you refer to the Ray Milland Uninvited from the 40's, I'll agree that it's quite good and very atmospheric - I have the laserdisc as it is not on DVD and I'm sure there was a VHS at some point.

The original version of Dark Water was SO much better (and creepier) than the remake. I also enjoyed the original Grudge (Ju-On) but thought the remake kicked much ass especially the unrated version.

I'll 2nd Devil's Backbone and the Eye as enjoyable and spooky and worth your time