We used to buy this stuff called: Marie'*...or Maria'* Blue cheese. I don't know if this was only a local item, or if it'* available everywhere, but it was real thick and delicious. It was also found in the cooler, and not on a warm shelf. I would say that'* one good way to find the better stuff....look in the refrigerated section at your local stores.
Also, there are these cash-n-carry type of places around here, that usually supply restaurants and so on, and they sell all the best stuff there. One problem is most sell the good blue cheese in a 5 gallon bucket. I found a place here that used to sell it as small as a 1 gallon jar. Not bad to split with a friend, or 2...
Other non-conventional idea, but not a bad one would be to look online for a recipe to make your own.......you'll probably never go back to store bought again........ or go to your favorite restaurant, where they know you, and ask them to sell you a quart or a pint or something. You might pay more per amount, but we're talkin' about obtaining the best you can find, and not the cheapest you can find.
I don't like the stuff some of the local pizza joints use here...it has become almost mainstream to dilute it with mayo or something that tastes like mayo. Some places serve it as it comes, and that'* usually good thick chunky blue cheese. I can fully embrace your "need" for a better quality blue cheese dip..
Good Luck........... Sam