Though technically within Austin city limits, it takes a solid half hour to drive out to the Austin 360 Ampitheater. The trip, however, is worth it — out in the middle of nowhere, Texas, you have vast skies, wide-open plains, and an outdoor venue that regularly hosts some of the best musical and comedy acts touring the United States.
Mumford & Sons and the Lumineers have recently made their way to the Austin 360 Ampitheater, and acts like Flight of the Conchords, Maroon 5, and Wiz Khalifa are upcoming in the next couple of months. Check out the website for all scheduled events.
A little tip — go for the lawn tickets (much cheaper), get there early, and bring a blanket to spread over the grass as you sip on an overpriced beer before the show. You won't be right up against the stage, but they're the best seats in the house.