I would call you MVP, though I have no idea how. That said, of anyone's actions, Amumu's actions were the one's that had the largest effect on the game. Both Twisted Fate and Warwick would have died on night 2 had Amumu not ulted there, leaving both investigative roles dead after night 2. The entire game could have had a heavy swing in the opposite direction.
EDIT: Also, no one's ability could have directly saved you from dying as a result of investigating Singed. If you chase Singed, you die, everyone knows that. There may have been an interaction in there that, if it had come up, might have saved you (but I am unaware of one) but if there was, it was the type of interaction that would have likely not occurred.
EDIT: Also, no one's ability could have directly saved you from dying as a result of investigating Singed. If you chase Singed, you die, everyone knows that. There may have been an interaction in there that, if it had come up, might have saved you (but I am unaware of one) but if there was, it was the type of interaction that would have likely not occurred.

