Oh Angie, I feel your pain. When we were having such problems with the GSD's next door it just about drove me nuts! Thankfully the female went with the boyfriend when he left so that just leaves the male (Max) and he's not as bad as he used to be and she actually watches him much more since I said I would be calling the warden if I caught him in my yard again!
We did put some tall bushes, gravel & electric wire on one side of our yard (but the electric wire is all the way around the yard-top and bottom, so I don't think that's mean at all) to keep Angus from always running & barking after the neighbors grandson when he was over there (hey, he just wanted to play).

Here's a picture of it all the way down

and one straight on

I hope you can figure something out.

But I really think the electric wire would do the job!