Flamingo Automotive. I've mentioned them quite a few times on here. Doesn't look like much on the outside, but Joe Lamping the owner has an SCCA history and is currently an HPDE instructor, in addition to being a very cool guy and very honest and knowledgeable business owner. You can tell within 2 minutes of talking to him that he does this because he loves his work, not just to pay a mortgage. His shop does Japanese and German cars, and he himself tracks a Techno Violet E36 M3. I go there for everything not covered by either warranty or Ultimate Service, including track-related work and mod installs.
Black Forest also has an outstanding reputation. I've never taken my car there even though I now live closer to them than Flamingo because Flamingo has always done right by me, and I feel that should be rewarded with customer loyalty -- but if I were looking for a great nearby shop today and didn't have a history with Flamingo, that's probably where I'd go.
And yes BMW of Austin is also excellent. My SA Thad Tucker has always impressed me, as has everyone else I've met there. And the facility itself is beyond belief. Not many other dealerships have a movie theater complete with La-Z-Boys and a ~110" screen fed by a 500-disc Blu-ray player for you to hang out in while you wait for your car....