"Heavens above" is so old fashioned that you would get a laugh out of it. I put it right up there with "Oh, my sainted aunt!"
It leaves off several that are vulgar, like "No s**t!" (This can also be "I already knew that - so be careful even if you are okay using rude words.)
There are so many ways to express surprise.
I think I over-use "You're kidding!"
I tend to use "Gracious!" as a very neutral response, which I think it better than "That could only happen to an idiot like you!"
Good golly, Miss Molly!
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