Whip-in. Its right off i-35 and oltorf (about 4 miles from downtown) and has 72 taps, great bottle selection, and awesome indian food.
The Ginger Man is in the middle of downtown so you can get a good tap selection then easy walks for bar hopping.
I also love Easy Tiger. Its got a really good tap section (including a DFH 60 min. tap attached to a Randall the Enamel Animal) and good house made pretzels and beer cheese.
Its easy to find good beer here, almost every restaurant is going to have something local on tap. Defiantly get some Live Oak Hefe if you havent ever had it. Austin Beerworks has awesome beers as well.