Around here, the three major kinds of "BBQ" are ribs, pulled pork, and (less frequent) brisket. The pulled pork, to me, is pretty constant (ignoring the BBQ chains). The rubs vary all over in style and even type, the brisket can be pretty bad at some places, dried out, tough, not tasty. Fox Bros. IMHO has the best brisket of any place I've tried, but when I venture to a new place I USUALLY get pulled pork. But I suspect some places may have great ribs and mediocre PP and maybe not offer brisket.
I kind of wonder what makes the top ten truly elite. It would be fun to try one and then try #50 and see if I could discern a difference. I'd guess #50 in Texas might be better than anything in GA, or at least top ten in GA.
The sauce variable is another one in the southeast of course. A lot of folks here thing BBQ has to have sauce, and they may rank restaurants on how well they like the sauce.
The best ribs I ever had by far were cooked in my backyard on a trailer rig by some boys from Missouri. I've never come close to them, and the notion they needed sauce was foreign to my lips. They didn't, at all, need any sauce. The funny thing is it was for a work dinner and I had about 20 coworkers from Japan sitting in my backyard eating ribs, corn, baked beans, and water melon. They seemed content.