that was the first episode. "Death has a shadow". the actual line was:
stewie: you know mother, life is like a box of chocolates. You never know what you're going to get. You're life, however, is more like a box of active grenades!
Now, I offer you one last chance for deliverance. Return my mind control device... or be destroyed!
Lois: oh, you just want your toy back... ok, here you go honey.
Stewie: Yes... well... Victory is mine!
Runs off...
explosion...
Stewie: Ahhhh.. *censored* you all!