Open Source Vapor is one of the best vendors out there, don't be fooled out by their simplistic website.
1- I tried OSV after reading it on here and tried to give it a shot. Joshua, who I believe to be the owner, is really a great person. He patiently and quickly answered all my questions and helped me a lot during my ordering process. He even mixed a special flavor for me just because I asked so. International shipping is fast and very cheap.
2- Prices. Price/performance ratio of OSV Juices are really great.
3- Ability to customize your orders. You can thin your juice for tank or double your flavoring. Whatever floats your boat.
4- Flavors itself. I tried Peppermint Mocha first and when I vaped it I really felt as if I was sipping a peppermint mocha in Starbucks. Tried Blueberries & Creme, it was really smooth and sweet. Not over sweet, not artificial taste a very simple yet great taste.
5- All juices arrived in glass bottles with drippers in them. No leakage, simple and good labels.
I would suggest everyone to give OSV a try, their prices are really affordable and you won't be disappointed.