I have a lot of RTA's, but lately have really been loving my Subtanks. I have the original, the Plus, and the Mini.
The plus and the original hold massive amounts of
juice, and look really great on my larger tube mods and my Sigelei 150 box mod. The mini holds plenty of
juice, and looks great on anything.
They are really easy to fill and to rebuild without emptying
juice, they give great flavor, and they normally don't leak. They have the added benefit of using OCC coils, so if you are out and about and your coil gives out, you can just throw one of the prebuilt ones in.