The question should not be who are good breeders, but what environment do you have for growing and what genetics would best fit that environment AND suit your palate for quality of high effect and other requirements. Breeding is often a trade off. If you are growing outdoors its likely that you will not be able to run most indoor varieties because of powdery mildew, bud rot or some other problem like pests. If you have a perfectly controlled indoor environment then by all means go and buy from some good breeders to suit your tastes. Don't stagnate with buying one breeders stuff - you want to explore and educate yourself.
Personally I don't run many modern hype weed. Very occasionally I will run something that is currently available to buy. But I'm a sativa lover and I don't like indica to get mixed in too often. Most of my seed stash I made myself or was gifted by friends. There are some breeder packs in there from places like Doc D, Cannabiogen, Ace Seeds but I'm not really growing those anymore. Last bunch of seeds I popped was all different landraces crossed to a Tom hill original haze male. Tried Senegal, Zambian copper, Malawi Gold, Mulanje Malawi, Punto Rojo, Ko Chang Thai, Hmong hill tribe Thai, Durban poison 70s, Zamal, golden tiger, flying dutchmen original haze.
Just got to make friends with the right people and search the right stuff that you like and it will come eventually
Golden Tiger x Tom Hills Original Haze