Definitely play Pease park. I can't recommend any others as MUST plays, but I hear that the course in Manor is really good too. Stay away from Wilco if you are used to throwing rollers...lots of rocks jetting out of the ground everywhere. In fact, in Austin, there aren't many courses that the roller is very reliable on at all due to uneven rocky ground. I'm a big fan of Pease park. Be sure to check it out. It is in the heart of town too.
