The Truth Isn't Out There - SPOILERS

Rating: 8/10 (23 July 2003)

When I saw the trailers for this, I was really excited to see it. I expected a smarter, scarier "Independence Day." When it came out, my sister saw it first, and she wasted no time in tearing it to shreds, telling me how stupid and boring it was. End result: I waited to rent it instead, and recently sat down to watch it with no expectations at all (probably the best way to watch any movie).
I thought it was terrific. Since I wasn't expecting another Alien Invasion action flick, I could settle in and accept the alien subplot for what it was: a plot device designed to give Graham a chance to reexamine his lost faith and reconnect with his family. While the nighttime chase through the cornfield was tense and the Brazilian party video was really disturbing, the two most gripping scenes were both quiet conversations: Graham & Merrill's discussion on coincidence/luck vs the divine plan, and the dinner scene where the wall between Graham and his kids finally comes down (this scene is played perfectly by everyone).
And, to refute what some others have written here, I didn't see the "faith vs luck" thing as being explicitly pro-religion. All he's saying is that if you believe in a higher power, then it's easier to build a happy life for yourself. But you can doubt and still be happy; it's just harder to live with the fear that you're alone in the universe. In the end, it's not religious faith or the Benevolent Hand Of God that saves the Hess family from the aliens; it's the fact that they're a strong family that looks out for each other.
People have complained about the "flat" acting, which seems to me to have been intentional. In a nice change of pace, Mel Gibson gives an atypically quiet performance; those used to seeing him goofing around in the Lethal Weapon movies might be disappointed. Joaquim Phoenix continues to develop into a rock-solid character actor (watch him reacting to what he sees on TV & in every scene he's got with the kids), and the bond between the brothers was deeply felt, as well as the void in the family. Both of the children were excellent; Shymalan has a real gift for casting and working with child actors.
A few words about the aliens, since so many viewers wrote in to share their disbelief about the way they behave. It's never confirmed that the crop circles are for navigation. That's just what the reporters are speculating. The crop circles could have religious meaning to the aliens, or maybe that's how they mark their territory. Maybe it's just psychological warfare, designed to confuse us and distract us from the other things they're doing.
It's also never confirmed that they need us as a food source. Indeed, if water is lethal to them (see below on that), we'd be the worst thing for them to eat (we're 80% water!). Maybe they view us as a threat and this is a pre-emptive strike. Who knows, maybe they only mate once every 30,000 years and human bodies play a role in it.
And here's another theory: maybe the universe is full of alien races, and we were lucky to be invaded by one of the less-intelligent species. It's possible that in all their explorations, they never encountered water or doorknobs before coming to earth. And why are there aliens randomly sneaking around Pennsylvania farmhouses and Brazilian birthday parties? Because they're idiots. Maybe Shyamalan was having fun with the accepted wisdom that the alien invaders would naturally have to be much smarter than we are.
If you can drop your expectations and accept that this is a movie about one man coming to grips with God, finding his lost faith, and repairing the wounds in his family, and that the aliens are just a means to that end, then you'll probably get something out of it. If not, then you should probably watch "Aliens" or "Predator" again instead.