That's a little like your sister asking you who the hottest girl in the room is, right in front of your wife...
There are established seed breeders here and breeders just starting out. For a beginner (such as myself) it may be a better
call to go with a breeder that has an established reputation and and a documented track record of stabilized genetics.
There are also a lot of testers here that test for multiple breeders and a question like that can put them in an awkward
position to answer.
It also depends on what you're looking for, how you'll be doing it and how many you'll be attempting.
I, myself, decided to start out with Sweet Seeds Dark Devil. But I may bounce around for my second...
The choices now are overwhelming. But I may very well just go to Sweet Seeds Sweet Special Auto if I
really dig the Dark Devil. Not enough time to try all the appealing offerings...great problem to have.
I would suggest identifying what type of weed you want to grow...(indica vs sativa vs hybrid)
Then identify the potential sizes and timeframes you can work with.
Then identify what flavors, nuances you're looking for and start hone in on it from there.
Also...Tons of Smoke reports on this forum that come in real handy in giving you objective
opinion (mostly) rather than just simply the company line.