Panic in Year Zero
Great film - Milland is really god in it. I have a copy of itknocking about if u are interested. Invasion USA (not the Chuck one) and This is not a Test are both similar (not quite as good) but are worth watching.
There's also a decent Brit one called No blade of Grass..
I actually liked the remake of The Day The Earth Stood Still - granted i was a bit pissed but i liked the over the top biblical refferences and Gort being made up of Nano technology (well Nano technology tha you could see when it suited the scene)...
Will Smiths kid needed to die in the first mins though..