Three of us went to see The Strangers and the two who stayed to watch agreed that it’s well above average…until the second half. 
The problem with these films is that they make a very definite and difficult point; the scariest thing in the world is other people.  In terms of cruelty and violent caprice, the creature from the black lagoon doesn’t have anything on us.  We create monsters and infuse them with everything that’s worst about us.  We are the things that go bump in the night. 
The problem Strangers runs into is that it doesn’t really know how to deal with this fact.  It was disappointing to see tension lovingly, meticulously increased, and then thrown away because Strangers couldn’t figure out how to keep it.  The killings (that’s not a spoiler if you own a television) are just woeful.  And much of the ending is extremely campy, but this isn’t supposed to be a campy movie.  
The Strangers doesn’t make you mad (it’s worth seeing in the theaters) it just makes you feel a little disappointed.  It’s an enjoyable waste of time but it could have been much more–it could have been a truly frightening film.  It goes from playing on our deepest fears to slap-yo-mamma silliness.  Or so says I.

The actors (too lazy to look up names)

Liv Tyler: In the scenes they asked her to, um, you know, actually ACT, she was very good.  In the others…not so much.
Main Guy:  This man has the ability to, alternately, look like all the male Afflecks.  He gives a fine, sort of bland performance.
Friend Guy: Pretty good.  Does his job, which [spoiler alert] is getting shot.


Me: I stand by what I wrote.
My Friend: My friend loves gore and is frightened by it.  He agreed that the gore (and to be fair, there isn’t much of it) was terribly done.
My Girlfriend: Fled during the first third of the movie in fright.  This, I think, reinforces my point that Strangers was doing quite well but got lost somewhere around the middle.

Final Verdict:  Go see it.  It’s fun.  It could have been great.