I got two samsung 25r on amazon (http://www.amazon.com/gp/product/B00NUI45AU/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 from seller VapeGrocery) and they appear to be authentic and have been working well

I have only bought batteries from lightningvapes.com personally, but here are the two that styles I own sold on Amazon. Both listings show reviews stating true authentics multiple times.

Efest 18650 (2 for $13.92)

Samsung 18650 (2 for $13.99)

Even if they were Samsung 25R's I wouldn't recommend ordering battereies from Amazon. Here's something I posted last week about batteries from Amazon:

I purchased these a month ago: http://www.amazon.com/gp/product/B00NUI45AU?psc=1&redirect=true&ref_=oh_aui_search_detailpage Didn't realize at the time the vendor was in China. They look legit just like yours look legit... However I had to sit them just right in my Nitecore charger or they wouldn't read. Then when putting them in my iStick 100, I would press the button and two seconds later get 'Low Battery' or something like that. They've sat ever since. Probably gonna toss them. Not worth messing up one of my mods or my face/hands for $20 especially since I have 5 or 6 mech mods. I'll never buy batteries from Amazon again... Can't be too careful about batteries.... What happens is that 10 different vendors can sell the same item. If you click on the 'XX New and XX Used' link you'll see a bunch of suppliers listed for the same product. Depending on the price and if there's Prime involved, two people can hit the same link and get two different vendors that come up.

Illumn has a Black Friday sale right now where you can get Samsun 25R5s for $4 per + shipping. That's your best bet.

I have a $20 amazon gift card and am looking to get some new batteries. I'm looking at 2 different batteries (unless someone knows of something better), Samsung 25r and LG HE2. After doing some searching on ECR, it seems the Samsung 25r is preferred over the HE2. Is most everyone in agreement on that?

These are the two I'm looking at:

Samsung 25r 2pc/$17

LG HE2 4pc/$25.50

Health Store and More. Theyre actually the #1 Best Seller in 3.7v batteries, you believe that? I ordered from here earlier and these were just fine.

Also, I found it kind of odd that Health Store said they sold assorted colors blue and green.