If you try madvapes, be aware that the CUSTOM china e-liquids had the nic added to it at madvapes. They use a high consentrate, so very little is added and, depending on your taste buds, you probably won't be able to tell the difference. If you have really keen taste buds tho, you probably can taste the differance lol. (I ordered one bottle of custom before I knew, got to researching why it tasted different and found the above information. Nuff said??? lol)
Their china
e-liquid is straight from the factory but only available in set nic levels. You can get 24 and 0 and mix to whatever you like, and keep full flavor in the process.
edit: dktab, 555, and ry4 are some of my favorites and well worth trying imo. Another thing I wanted to mention is that the hangsen e-liquids have been getting good
reviews. It's a little pricey for me but you might want to give it a try.