Off the top of my head in no particular order:
GT Distributors
Austin Gun Liquidators
Heritage Firearms
The Gun Store(Cedar Park)
Reds Indoor Range(2 locations)
I've had great experiences with those listed below and check in on occasion.
GT Distributors: counter gets busy but they'll take care of you when it's your turn. $15 transfers. They have a lot of LE only items which can be hard for non-Leo's to look at and not be able to buy. great supply of Glock trade ins and occasionally some other good trade ins (sig, s&w, beretta)
Austin Gun Liquidators: limited selection but they'll get you what you want at a good price. $25 transfers.
Heritage Firearms: nice guys. Some good stuff. And they'll also give you a good price on anything they can get their hands on.
Reds Indoor Range North not the most competitive on their stocked items or ammo, but I enjoy the range. And they have a good spread of guns on hand.
Storied firearms: the guys I've talked with are great. Thy have some older shooter and will likely order whatever you want.
Academy has good prices on common buys and cabelas has the largest selection.