I love Tainong Seeds and Kitazawa for anything Asian.
Territorial or Johnnies for ordinary crops.
NEseeds or Hazards for bulk size packages.
Baker Creek for rare heirlooms. If you search the Baker Creek site hard, you can find a "Bulk Vegetables" area with good deals. Also, Baker Creek sometimes advertises a relatively high price for a small number of seeds, but then puts 2-3 times as many in the packet as promised.
I also like Ed Hume.
