Very realistic and believable fallout of an alien invasion on human society. Minimal reliance on special effects and alien monsters made this much more convincing and cerebral to watch.
The story focuses deeply on a post apocalypse power struggle and politics - a clear human vulnerability that any occupying force would employ to their advantage. You usually don't expect such depth in an alien flick. Everything seems very plausible to expect after a world changing event - make you keep asking yourself "what would I do if this choice were up to me".
And don't forget those amazing explosions, shock waves and sonic booms... They would be truly terrifying if encountered in real life!!
Saw up to season 2 - waiting to access 3.