They are both correct! The first sounds more like a favor, while the latter sounds more like revenge.

As others mentioned, “for you” , in this context, is gratitude. You want to return a favor, for example. “To you” sounds physical or sexual or as someone else said, it could be vengeful, like getting back at someone.

Both are correct Lepel. The first one sounds like there is a positive intent behind the action, while the second one can be both positive and negative.

I agree with the previous person's comment. "I hope to do the same for you" is the more common expression, and is used to express gratitude to someone for something they have done.