Hi Jenna,
These 3 suppliers are all SaleHoo verified, offering high quality organic products. I've highlighted their differences below for better comparison.
Honest Green: They have a one time processing fee of $50 to set up an account with them. Their drop shipping fee costs $25 compared to Bangalla's at $19.95, and Speedy Dropship's free setup. Also, they don't offer any returns unless the product is defective, or have shipped the wrong item/s. Of all these 3 suppliers, Honest Green has the most selection of organic products and brands (they even have organic supplements for pets).
Speedy Dropship: Like Honest Green, this supplier also does not offer international shipping but it offers a free dropshiping account. They even provide a data feed for you if they approve your account with them. They also offer sample products to try if it fits your market. Their products come with 30-day warranty should your customers request for return/exchange.
Bangalla: This supplier offers international shipping unlike Honest Green, or Speedy Dropship. Their wholesale account setup if free. For opening a drop shipping account with them, apart from their one time setup fee of $19.95, they charge for their services with a standard rate of $8.95 per month. Bangalla also accepts returns/exchange of non-food items within 30 days of purchase. And just recently, they're now offering direct fulfilment to Amazon FBA warehouses to retailers.
Hope this helps.