The rubicon LJ has the same upgrades a regular rubi would that ^ hit on: Upgraded/reinforced transfer case with fixed flange DS output, 4.10 diff gearing, f/r locking diffs, D44 axles, and of course the decals whatnot. That fixed flange on the TCase prevents you from having to buy an SYE if you choose to lift it. Save some cash there. The D44s are also much stronger than the stock D30 or D35s and can run bigger tires. Stiffer spring rates in the suspension (but same height of coils).
If you're on the fence, look around the forums. For every post of people wishing they hadn't gone for a rubi, and bought a sahara/sport/x instead, you'll find at least 10 posts of people wishing they had gone rubicon. Rubis also hold their value much better. Double edged sword... More expensive to buy, better resale value if you decide to sell it.
You won't be disappointed with a Rubicon Unlimited. I promise.