I loved Signs. My DF didn't like it at all. Thought it was silly. And although he said it was "predictable" he still jumped out of his skin at all the right places.
I don't do well with scary, gory movies. They give me nightmares. I have far too vivid an imagation to watch things like that. But M. Night's stuff, now that's another animal altogether.
He plays with your mind.
As for the smart aliens in Signs doing some pretty dumb things, well we're supposedly pretty smart and we do some pretty dumb things. You'll notice that none of the places they aliens landed was near water, so they were trying to stay away from it while finding places that would provide what they needed. And after having looked at their hands, I don't know if they would have been able to turn a doorknob easily. I don't think it was that they were too stupid to be able to figure it out, I think it was a physical limitation. OTOH maybe they don't have doorknobs where they're from, and they had to figure out how they worked first before they could use them.
Frankly before I saw Signs I was convinced the alien thing was going to turn out to be a hoax and there wouldn't be any aliens in the film.
Unbreakable I've only seen on TV, and I want to get the DVD now. The first time I saw it I only saw bits and pieces of it, the second time I saw it all the way through. There definitely wasn't as much depth to the characters as in the other films, which I think led to a lot of the subtle cues and hints being missed. I think they're there, but they're way too easy to overlook.
Looking forward to seeing the Village sometime.