i'm a big fan of attitude seed bank. great shipping, fast, stealth and they give you free seeds!!

So many amazing strains out there. My next shipment i'm grabbing some White Widows from Green House Seeds, a very reputable breeder. I would also recommend Super Lemon Haze by Green House Seeds. They are the original breeders of this strain which won the cannabis cup in 2008. My friend just got back from Amsterdam and said Super Lemon Haze was the biggest thing in all the coffeeshops and the best weed he smoked in Amsterdam.

Other good breeders are Reserva Privada (OG Kush breeders!), DNA, Barney's Farm, Mr Nice Seeds, G13 Labs, etc