So John Fullilove of Smitty's in Lockhart had an interview where he talked about what was popular in Smitty's when was growing up. Seems like he mentions it in other interviews as well. When he was growing up - he's shy of 40 - the more popular items served were clod, sausage, and smoked pork chops. He talks about brisket as a more recent trend.
Pretty interesting considering the trifecta in which Texas BBQ joints are now judged is Brisket, Sausage, pork ribs.