Metallica or ACDC

My wife and I got into the discussion on who is better , ACDC or Metallica. We both agreed that both are awesome but if you had to pick, who would it be? For me it would be ACDC. I was fortunate enough to see them in concert in the late 80's and it was simply awesome. I like Metallica and I have seen them several time, but for me it is ACDC. But RUSH is my fav group of all time.