I buy most from
www.emblibrary.com I am a lifetime member of
www.designsbysick.com I wait until sales and get a bunch!
www.bfc-creations.com is wonderful too! I have bought my thread from
www.bfc-stash.com and have been VERY pleased with my purchases
http://www.myfloriani.club/index.php has wonderful thread and if you ever get a chance to check out their stabilizers / software please take the class. Not associated with any of them, just a happy customer