I don't think I have favourite brands so much as favourite styles.
I used to be very fond of the Hom bikini briefs and thongs, but at a certain point in time I stopped buying them because the price in stores skyrocketed in response to a fall in the Australian dollar. (This was before online sales really took off.) Now that our dollar is strong again, you would think the prices would fall, but it doesn't seem to have worked that way. What seems to have happened instead is that very few stores stock them, and you HAVE to go online to get what you want - then the local retailers scream blue murder because Australians are buying online from overseas instead of supporting their local industries.
Excuse me while I go get the violin...
I'll probably buy more Hom at some stage, but in the meantine I have discovered lots of other brands, Currently I think my favourites are Joe Snyder.
There was a very nice and cheap brand called Maxx, made in China and sold in our Target stores (not the same chain as the U.S. Target but the concept is similar). I acquired quite a number of Maxx thongs and G-strings. They now seem ot have disappeared from the shelves; in fact last time I looked in Target there were no thongs of any kind and not much in the way of briefs either, very little in the way of underwear smaller than boxer briefs.