The grey Panasonic batteries we all know and love!
Currently this is the best USA deal going. Fasttech is slightly cheaper but some people want their batteries quicker. I aim to please. This deal is for 4 cells.
In my opinion these are the best 18650's money can buy.
These are rated for 10 Amps - great for sub-ohm builds.
I have also provided the link to Fasttech that is a bit cheaper but longer shipping time.
USA WHERE: http://www.amazon.com
CHI WHERE: http://www.fasttech.com
$22.98 + $4.99 shipping