Here's a list:
The Houston Flying Disc Society
Don't play Mazola unless you plan on losing all of your discs! It's right on the
bayou.
My favorite are the two courses at Tom Bass regional park - they've held World tournaments on the outside course, I believe. The two courses are off of 288S. Jack Brooks has nice courses too.
There's also The Woodlands and Kingwood, but the Woodlands gets crowded. Kingwood is actually a private course, so be careful if you try to play it.
UH Macgregor is alright if you're trying to get in a quick game - we take our dogs there because we live in the area. :-)
Agnes Moffitt is home to many league players - I don't personally like it because groups stack up on the weekends.
Um...there's a new course