I think there's nothing more important than love.

I think it's important to know what's hot and what's not.
今何が流行っているか、流行っていないかを知ることは大切だと思う。

I think it's important to share happiness and success with a family.
家族と幸せや成功を共にするのは大切なことだと私は考えています。

I think it is important. So tell me. Didn't you already break up with her when you started dating me?
大事なことだと思うよ。だから教えてよ。私と付き合い始めた時、あの子とは別れたんじゃなかった？

I think that's really important.
それは本当に大事な［重要な・大切な］ことだと思う。

I think there's nothing more important than love.
愛が一番大切だと思う。