As mention there are lots of good restaurants in Sundance Square and in the Stockyards. Cattlemans was mentioned for a good steak, while that is true they are not as good as they once were. Riskeys Steak House (next to White Elephant) serves a better steak, IMO. I wholeheartedly concur with White Elephant as a watering hole or a great place to listen to good music (Shaddy - I dont think the Longhorn is open any more...) For GREAT Mexican food, a little hole in the wall called El Asadero, on Main between the Stockyards and Downtown, is where I would go. However, the atmosphere is nowhere near that of Joe T.'s. Most of the staff speaks little to no english and the novellas are always on, so you know its gotta be good.
Bass Hall was also mentioned, try to catch a show there if you can. The venue is unbelieveable. There is also the Kimble Art Museum and the Omni Theater at the Will Rogers complex. Minor League baseball team Ft. Worth Cats play at LaGrave Field just across the Trinity River bridge from the courthouse, again on Main between Downtown and the Stock Yards. There is a Brewery (Rahr's - I think is the name) in Ft. Worth that may offer tours.
I hope you enjoy your trip to my city. Let me know if you have more questions or want more info.
Scott