I can't believe no one has mentioned the PRECIOUS!
It comes in 4 sizes, so it is the perfect size.
The Precious is the smallest of it's type in all battery sizes.
It is available with 3.7v and (soon) 6v.
It is VERY pretty.
It has the touch activated switch with variable voltage!
It has vent holes in front of the POSITIVE end of the battery, where it would vent.
If it gets dirty, the maker recommends soaking it in alcohol and baking it!
It will not go off in your pocket.
It comes with a 510 adapter.
It has low voltage protection.
It is just plain frigging sweet!
(I have one on order, the S size, trying to be patient)
Just my $0.02
