Well, of all the places mentioned thus far, the most iconic (not necessarily the most famous) are Black's in
Lockhart, Louie Muellers in Taylor, The Salt Lick in Driftwood, and Cooper's in Llano.
I've never been to the Coopers in Austin but if it's the same stuff as in Llano, I'd agree with the above assessment.
I've also never eaten at The Salt Lick but have driven by it many times. The setting is out of a storybook. It is just gorgeous!! Food is supposed to be pretty darned good too
Once again I cannot swear to this about Salt Lick, but can for Cooper's. The food is done open pit versus in a smoker so it's a bit of a different BBQ experience but still outstanding!! If you go to Cooper's be VERY careful. They are world famous for their pork chops and one of them will feed about 8 people
They are huge. You walk up to the pit and see all this gorgeous food sitting on a grate over the fire and you want a little of this, and a little of that, and a chunk of a couple other things, then some sides, and of course dessert. Next thing you know it's a $40 lunch and more food than you'll ever eat unless you're in training for an appearance on Man vs Food. They probably go through more to-go boxes than they do food...but it's fantastic!! You'll eat good leftovers for a week
Now to the final nugget on this one. One place you can go for excellent BBQ, great service, a really nice environment, and a menu that is far more than just basic BBQ staples is Casa TX
You may have to wait a couple hours but you won't do it standing in line. You can do it lounging in the pool with a cocktail, glass of wine, or a margarita, and some great company (that will be Tracy. I'll be cooking).
Reporting from just north of Austin,
Robert