Right now its definetely Eric. Jordan is starting to really flourish as a player. He's got great hands, great vision, and plays the game with an edge. That can also be said for the other three brothers which is why this is a tough question to answer.
We can't say who is the best at this point. Jaret and Marc aren't even in the NHL yet but when they are we can figure it out. But how could you compare Eric and Jordan, yes Eric will get more points but Jordan is a profound penalty killer. They're all good at different things.