High on you

That's pretty close. You can get high on drugs or alcohol. It means that something makes you feel very good. If you get high on somebody, that person makes you feel very good.

Thanks for the quick reply.
So it is more romantic/friendly phrase than it is formal? (What I try to ask is: somebody who doesn't like you in friendly/romantic way wouldn't say that to you, right?)

It's definitely informal and more than friendly. It's almost to the point of "I love you." The person saying it would probably actually be in love with the person s/he said it to.

Thanks a lot

No problem. Good luck with your English study. It's a crazy language.