Albertson's usually carries good full briskets. I have also gotten them at Frys/Krogers - though they don't always carry them.
I agree with DanBono - I used to live in Texas and bought my briskets at a variety of places (including the above grocery chains and Costco and never could tell a difference between the different stores. I now buy at Costco/Fry's/Albertson's in Arizona and get the same good quality.
One tip - when selecting a brisket. drape the brisket over your hand/wrist. If it is stiff as a board - try another one. If it flops over on both sides, it is a tender brisket. The long smoking makes even tough briskets tender, but if you start with a more tender brisket - the end result is even better. The more it flops, the more tender it is to start with Photo below is a really nice one I got at the local Albertson's. (I test them at the store while still wrapped in plastic - they don't bend as much, but you can still see a difference.