Don't forget about the carp too. There are some giants running around in the Guad. Since the Guadalupe is a tailwater, I find that it fishes really well for bass during the summer as long as you are up early enough to avoid the tubers.
With that said, Barton Creek is my favorite place to fish and if you've got a spare morning, Lost Creek is a great place to kill a couple of hours. The creek is running really low right now though which is a double edged sword because it makes the fish easier to find, but it's just not as much fun as it usually is. We do need some substantial rain soon to recharge everything or else I may be making a post on here to recruit some volunteer to help save some fish by moving them down to permanent waters.