OMGAWD I WASN'T THE ONLY ONE WHO THOUGHT THIS!
From MSN:
Worst Ending: "War of the Worlds." Leave it to Spielberg to ruin a film. The man just doesn't have the guts to finish any other way than with a fantastically happy ending. So, let us get this straight: Billions of people died when Mars attacked, yet everyone in Tom Cruise's family -- including his son, who ran headlong into a blazing hillside battle -- survived? Lame.