I have been egging for almost 3 years now, and I really love my LBGE. I've had lots of great cooks on it - heck I think that it is worth getting an Egg for the spatchcocked chicken alone, let alone t-rexx'd steaks.
The best thing I have ever cooked on my Egg was a rib roast. I prepared it as a traditional oven roast (rubbed with salt, pepper, olive oil, and garlic), and cooked it indirect, starting at 425 and cooking at 400 until rare.
What's the single best thing you ever served off your BGE?