I am a BIG fan of Dr. Greenthumb, in fact they are IMHO the best seedbank around and are top rated at the Seedbank Reviews;

http://www.seedbankupdate.com/su.html

I have grown out a lot of their gear ( Bubba Kush, OG Kush, U.K. Cheese, Endless Sky, Chemdawg, Iranian autos) and have never had any issues. Every fem'd seed I bought was female. I never had a single hermy or male flower. Everything I ordered was awesome and "as advertised." I cannot recommend them enough