MN_Maenad, I love Tea Source so I second this. I live locally so I didn’t think about them doing mail order. D’oh!
Tealyra is really good for Chinese and Taiwanese teas. My standard is dragon well but I’ve been trying out different types of white tea this year.
I just discovered today that my local San Francisco Herb Co., which carries loose tea in 1-pound bags only, also ships. The chief virtue of this place for me is the price, the 1-pound bags to for between $8 and $13 usually, depending on the variety (I have only looked at their black teas, other teas might be different prices). Their shipping might be a bit stiff, they wanted $12 to ship two bags to me here locally, so I canceled and I’ll just plan to stop by one of these days. I don’t know if shipping would be a lot more for a lot further away.
The bags are clear cellophane or plastic, so they’re not great for storage (for those partial bags where I can’t fit it all into a tin, I close them securely and keep them in a cloth bag in a closet). The quality seems fine to me, and they have a lot of variety.