Directvapor or myfreedomsmokes I've used both.Both have very fast shipping. MFS( myfreedomsmokes) may be a little bit less expensive but both are very good, solid online shops and have a good variety of mods, tanks, RBA, juices, etc.
I have also had good experiences with MyVaporStore.com
VaporDNA.com has good closeout sales if you're looking for anything older.
Ecig-city.com Ecig.comVapenw.com Myvaporstore.comVaporworld.biz myfreedomsmokes.com Eciggity.comVaporrange.comVapordna.com
I've used all of the listed cites more than once and have been happy with all of them.
I've used vaporbeast quite a few times and they ship fast and have reasonable prices and really good deals sometimes.
Huff and Puffers competitive prices and fast shipping ($5.99 for priority). Takes about 2 days to get to me (non-priority) but thats because im in the same state (CA). I also like using 3fvape because they have a 24hr section in which they ship the item within 24hrs it usually takes about a week and a half to get to me but their prices are great.
you can google mods, the site in the first or second ranks is also good.