Obviously, the Pico is super popular (I have many!), and so is the eVic Mini (I have several!), but I'll mention another one I like a lot: the UD Balrog 70W. Ergonomically, I think it's the most comfortable to hold of all my mods (LOVE the fire button), the menu's easy to negotiate, and it has a clever little juice catcher pad/ring around the 510 connection to absorb small drips.
This is the one I got, from FT.
I don't do TC, but if you do, you should know that it does Nickel and Titanium but not SS.
I also like the WISMEC Presa TC75W a lot, but it can be hard to find.
For a little bit more than your $70, you might consider the current special offer for US people (if you are in the US) of the
Jac Vapour Series-B DNA 75W ($79.99, free shipping from UK, a pretty big discount). ECF thread on it
here. @
DPLongo22 has one and is very pleased with it, so you could ask him about it if you are interested.
These are all small single battery mods, because that's just what I prefer.