My favorite panel was the first one we attended, "Spotlight on Southwest-Themed Sci Fi and Fantasy," which had four Texas authors talking about (mainly) the Lone Star State and its influence on speculative fiction.
I enjoyed that all the panel members were from or currently living in parts of the state where I had resided at one time or another. I also got a kick out of the fact that two of them were originally from my old stomping ground in West Texas, and their discussions about that region took me back there. They also name-checked several Texas writers, including Robert E. Howard and Elizabeth Moon.
Other panels were just as interesting (like the one on "What have Texas Infrastructure Failures Taught Us About the Coming Apocalypse?") and had may authors from around Austin as well as other parts of the state. We also heard from local horror author Gabino Iglesias, and went home with a couple of his books as well as his autograph.
The highlight for us was special guest Cory Doctorow reading an exceprt from one of his upcoming books, The Lost Cause. His writing captivated my spouse and I, and his take on the future, which can be described as "hopepunk" is one I enjoy.
So that was our first science fiction convention. I think we'll be going again next year.