Royler Rillion is supposed to be the Gracie with the best guard, but he doesn't compete much it seems. He's always there in the Gracie train, guy with light hair. www.greenwhaleproductions.com
For submission no gi grappling Roger. MMA Renzo or Royler but both are getting older. Up and coming gi bjj are Kron and Rhalan.
Royler has done excellently in competition, gi and no-gi, and I know that Renzo has done well in Abu Dhabi, so those two come to mind.
1. Royler (the most technical and successful competition wise) 2. Roger (big, technical, young, TONS of promise) 3. Royce (not as techical as the rest but very aggressive, good for MMA) 4. Renzo (well rounded, did well but not great in everything)
Helio. For MMA I think Renzo, Royce did better earlier on, but Renzo showed his ability to adapt and evolve, he modified his art more than Royce and learned more skills of the game.
It's Roger. In the past two years he's tapped Werdum, Saulo and Xande Ribeiro, Margarida, Jacare, Terere.. to name a few. He's only had a couple of narrow - and perhaps controversial - losses to Jacare, also an amazing grappling.