Personally, no favorite brands. Sister got me some packets of "Relaxing Lavender" mineral bath from Acacia a while ago which smells wonderful, and a very dear friend
sent me a kit of Dr. Teal's lavender items (epsom salts, foaming bath, body wash, etc.) which also smells wonderful.
I know Young Living is considered a high-quality essential oil company, but personally, I didn't care for it. Of course, that may have been because I didn't care for the person promoting it, but it just didn't smell like lavender to me. I've generally just bought what was in the health-food store that smelled like lavender. I don't really use the oil except to make a hydrosol (add a couple of drops to a spray bottle with distilled water) or to add a drop or two to a little water fountain in my living room.
Side note: there's a lavender farm near me that I visited not long ago. They grow their own and make soaps, etc. with it. I was going to buy the liquid hand soap but the price put me off, and when I used it in their rest room, it didn't really smell like lavender.
So I didn't buy it. But I still have the Dr. Teal's epsom salts and some of the Acacia for my bath. Since I haven't been home very much, I haven't had the chance to take too many baths, and it doesn't help that my tub drain isn't closing completely, so the water isn't staying in very long.