That' really cool! - tài kù le! 太酷了

That's hilarious! - hǎo gǎo xiào!  好搞笑!

Really? - zhēn de ma!  真的吗!

No way! - bù hùi ba!  不会吧!

Oh my goodness! - wǒ de mā ya!  我的妈呀!

Oh my gosh! - āi yōu wǒ qù!  哎呦我去!

That's freaking awesome! - tái níu le!  太牛了!