I own dozens, but most are on the vapocalypse shelf. Daily I have 2 box mods that I use at home, a couple of tesla stealths for out and about, and a couple of smaller istick 10w that I use at night on my bedstand (also make good flashlights for stumbling around in the dark) ...so I guess that comes to 6.
Now tanks are a whole different story. I have 18 or so that I use regularly. Most of them are filled with the same unflavored liquid. Two have flavors that I use on occasion. I like to do my filling once every few days.
Do you go through a lot of juice every day?