口语表达：太另我惊讶了！怎么讲？

Really?配上惊讶的表情

I was astounded a lot..

to my greatest surprise..

It's amazing!

正面:
It was astonishing.
It blew me away.
正反都可:
It was unbelievable.
方面:
It was insane.
当然还有:
Oh, my/sweet god/lord.
Jeez.
Jesus (Christ).
看情况用啦.

It's amazing!

So amazing!