I didn't sign up with Certified Angus Beef® Brand this year (logistical reasons only), but I am attending an expenses-paid BBQ seminar with them later this month.
The best burger that I have ever had is from Melvin's in Elizabethtown, North Carolina.
Elizabethtown is a small town, about 3,500 people today and even fewer people back in the 70's when I had my first Melvin's burger.
For me, the only way to get a burger at Melvin's is ATW (all the way) - topped with chili, creamy slaw, diced fresh onion, and yellow mustard.