Whisler's is my kinda bar. Super quirky, great cocktails, happy hour EVERY DAY, live music. What more could you want. They also have a large outdoor patio - great for large groups. It's in east Austin too, which is another bonus and in walking distance of a bunch of other restaurants and bars.
*HAPPY HOUR MENU, EVERYDAY FROM 4-7PM
Don't worry if you can't be there at 4pm, just show up when you can !