Which area of Ft. Worth do you call home?
On the West side you have Lone Star Scuba which has a sister shop in Dallas. This is one of my preferred shops and more or less the one I call my LDS. You also have Scuba Sphere and Diver's School (can't remember the exact name and too lazy to look it up right now even though I'm obviously already on the computer...lol) on the West/SW side. I haven't been to Scuba Sphere in over 10 years, so I really can't comment on them.
East side - We-B-Divin. Friendly staff, on site pool. Really in the HEB area, not Ft. Worth proper.
DFW Scuba shop is in Haltom city. I haven't been there.
Moving out of Ft. Worth and more toward Dallas/Carrollton. You have two of my other favorite shops: Scuba Toys and International Scuba, both with on site pools. Scuba Toys, as many here noted = Wal-Mart for Scuba divers. It's just fun to go in there and shop because of their large selection and I've always had great customer service from them.
International Scuba, just a good group of folk.
There are quite a few more in Dallas and Arlington, but I'll stop where I am so as to avoid writing a book on the topic.
I guess more than anything it all depends on brands you are looking for and various services. Some are more tech oriented than others, etc, etc.
Save dives,
Cyp