Volcano mini in a pcc. Small discreet. Nice vapor and taste, charge batts on the go. Small carts are its down fall but I can have 1 complete ecig, 1 batt on the charger and 5 carts in my pocket and it's the size of a analog pack.
Volcano Inferno (eGo type) takes 510 attys, drip tips, carts and cartos so it's very versatile. The 650mah battery acts like a pass through and the 1000mah battery last a couple of days for me.
Newest edition is a DSE601 E-pipe, battery will last all day, cartridge maybe half that. Also a good dripping vaper. Not one for continual use with my current juices, would have to find a blend that is smoother on the throat without losing taste or vapor production. I rotate between all of them but will leave the pipe at home when I go back to work after the holiday break ends tomorrow.