Watching 2 of the 3 Hughes brothers playing for the NJ Devils recently made me consider this question. Quinn, Jack and Luke were all drafted in the top 7 of the NHL draft and off to great starts to their hockey careers, especially Jack. But it’s certainly too soon judge them in historic terms.
Without giving it that much thought, the first that come to mind are the Jones brothers: Arthur played in the NFL for many years. Chandler is an excellent NFL D-lineman, perhaps a couple notches below the all-time greats. And Jon, of course, could be the greatest fighter of all-time.
I’m sure I’ll think of others, but would love for others to chime in.