I disagree with all of you. The most powerful weapon ever developed in any game has to be...
The God Diamond- Sims Series
Why many of you may not think of this as a weapon let me put the spin on it. With this you can create an army of minions who will do whatever your whim is. I mean sure, you have to look after these retard babies but still, it's infinite potential. I could just use it, take control of you, build walls around you, and then destroy the door. Or I could make a pool with you inside it and "forget" to add in a ladder and sit back with a bag of popcorn and wait until the bubbles have stopped. So I guess Sims may have succeed in making the best weapon ever... Which surprises me... Wait... Damn it, one of my minions has burnt a grilled cheese and the firemen are there, I guess I have to end this now.