JK Rubicon for smaller trails, JKU Rubicon for more climbing oriented trails.
I suppose that, technically, you could get more specific and go with the upcoming 10th Anniversay Rubicon in particular, as it comes with some additional upgrades over and above the typical Rubicon--real steel bumpers and higher ride height, for example.
All ego aside, Jeep has not made the Wrangler LESS capable as time goes on.
In their stock forms, skid plates, bigger tires, more power, more articulation, and front and rear brake locking differentials when not fully locked are all going to separate the JK and JKU Rubicons from the TJ/LJ Rubicons.
(That said, I still want a LJ Rubicon very, very badly.