I'll recommend
Austin Aqua Sports - the people are fantastic, very friendly and relaxed. They have a privacy-fenced outside pool that is surrounded by beautiful ornamental plants, a fully-equipped tech shop, on-site air and nitrox fills (quintuple filtered!) and a large assortment of rental gear. Their store is located on Lamar, just south of the Lamar/Guadalupe split on the north side of central Austin.
Things that set this dive shop apart from any other I have ever been to include:
First Friday: a unique and free backyard barbeque on the first Friday of every month which can see guest speakers as varied as Jim Bowden (world record holder on mixed gases in Zacaton, Mexico with a dive at 925 feet on Trimix 6.4% oxygen) to
Tanya Streeter, a champion freediver who recently captured national attention.
Austin Aquasports performs community outreach by providing pool, swim and SCUBA training lessons for physically and mentally disabled children. In addition, by hosting annual events benefitting the
Eels on Wheels and other organizations, they help to open up a whole new world to children and adults with disabilities. Underwater, they can move as they never have before!
They also host a weekly dive outing to Mansfield Dam Park at Lake Travis, during dive season, that usually involves a beer or two and lots of good company.
While they don't carry many lines of retail gear, they do sell ScubaPro and a few other brands. I have only bought regulators and other miscellanious equipment there, because I found that Henderson and Oceanic gear fits me better, but AAS is still my dive shop of prefence, hands down. I have taken all of my training through their instructors (I'm currently a rescue diver), and I have nothing but good things to say about the experience. Austin Aquasports is just a class act.