Resellers would be a whole 'nother can of worms. Their are dozens to hundreds of them, their is a severe lack of transparency and reliable information and misleading--even false--advertising and misrepresentation is widespread (even with many of the sellers that are somewhat 'trusted'). With the resellers and with grey market cells, its important to understand and accept that there are a lot of "known unknowns" and "unknown unknowns"This is really usefull. @Dzl definitely wiki worth stuff. Is there another guide for resellers ? Threads on resellers 100 pages long maybe we could find a way to organize reviews and valid tests together.

Here are some US based sellers:
ECPC
EVTV
EV West
Overkill Solar
@Craig sold EVE cells and might sell Lishen cells (I'm not positive)
@HighTechLab has US stock of CALB CA cells
Here are some of the discount resellers more popular on the forum:
Shenzhen Luyuan (Alibaba)
Shenzhen Xuba (Alibaba)
Shenzhen Basen (Alibaba)
Dongguan Lightning (Alibaba)
Changsha Deligreen (Alibaba & Aliexpress)
BLS (Aliexpress)
*This list should not be interpreted as endorsement or recommendation or any sort of seal or approval. Particulary the reseller portion. It should also not be assumed that sellers on this list are better than any others, what they have going for them is that--to varying degrees--they are known to us. But that is a relative term, many of them we have less than a year long track record with, some significantly less. It is a starting point, but due diligence is still required.
Manufacturers you can possibly buy from directly:
Frey, EVE, ETC, GBS
Other:
Lishen group buy