happy_terd
The list I am going to post is mostly made of random entries.
Some of them I have spotted in this topic, some of them I just stabled upon when googling for tea info.
I think some of them are American. Frankly speaking I expected quite a lot more links when you asked your question.
The first two shops I use myself. Unfortunately, they are British. One of them definitely ships abroad but I have not tried their black teas. Another one is very good but I don't know whether they ship abroad. You would have to call them and ask, they are not prompt replies on email.
Nothing But Tea
I love their
Sencha Uji.
So far, it is the best green tea I have tried so far. Next one would be
Large Leaf Green but I have not tried
all of them yet.
One of my favourites is
Lapacho which accordingly to the Internet is a wealth of health, no caffeine, so I drink it every evening before I switch off the lights.
They have a good selection of Rooibos with different flavours but after trying all of them I came to a conclusion that I like Rooibos on its own the best. A good tea if you don't want caffeine.
The second shop is
Teahouse Emporium from Bath. I have been there at the end of October and raved quite a lot about it here. Very good shop, pleasant and nice owners (I think honest as well, which is a rarity) with a cosy tea room downstairs. I would visit them weekly if I lived in Bath

I tried some of their teas.
Some of them I didn't like but just like
Stitchawl I realised flavoured teas are not my cups...
Code:
1 x Keemun £2.75
1 x English Breakfast £2.75
1 x Assam BPS CL Mangalam £2.95
1 x Pu-Erh Wellness Guarana £4.50
1 x Pu-Erh Aged £5.50
2 x Red Rooibos £5.00
2 x Roasted Mate £5.50
1 x Tokay Apricot £4.40
1 x Grenadine £5.00
1 x Lapsang Souchong - smoked tea £2.95
1 x Mate Coconut Milk £2.95
I did
not like (all flavoured teas):
Pu-Erh Wellness Guarana
Tokay Apricot
Grenadine
I do love their:
Keemun, Assam BPS CL Mangalam, Pu-Erh Aged (earth/dirt

), Lapsang Souchong (burning tired), Roasted Mate, Mate Coconut Milk (the only flavoured tea and I must be in a certain mood to want/like it)
The rest of the shops/links are not verified

and not all of them lead to their home page.
Organic Flower Power - Ireland
The Teahouse - UK
Bensons House of Tea - UK
Venalicia - Germany
Harney & Sons Fine Teas -
USA/Canada
Hibiki-an - Japan
Cup of Tea - (got thermometer from them) UK
McNulty's Tea & Coffee Co., Inc. -
USA
TeaSmith - London real shop, have not been there but was told by owners of Teahouse Emporium that they have good tea room with green teas
The Tao of Tea -
USA
English Tea Store -
USA
Northern Tea Merchants - UK
Long? Dunno