Zeiss, as the guys have said. But there is very little between Zeiss, S&B, Swaro and Kahles. I have the big Z6, and it is definitely not quite as good as the Zeiss (but is better in other respects). I think Docter optic is also up there, but that is word of mouth - i haven't used Docter.
Just basically choose a scope from somewhere that beat up on the Frogs last century and you will be right.
