My choice is the direct drive twisty Smiling Shark SS-5039/5038.
It has an IMR 10440, an XP-G2, no switch and only a tiny bit of spring. I avoid using fully charged cells in it, but the plastic reflector started to melt, so I junked a Black Cat for the aluminum reflector.
The pill is hollow, but the thick direct thermal star soldered to it makes up for that.
Runners up are the 3 x 7135, BLF Tiny10, two group SS-5039,
