Torches I am currently using:
Had an Ulrafire single XPG running off 1 X 18650 send to me as a freebie. Found it was very good and waterproof so sent for a few. Big annoyance was the silly flashes, so fitted my own driver, Max, Mid, Low in that order.
Other one is a bigger 4 X 18650 to 6 XMLs bough £20 of eBay. Wrote about it before.
Full power was direct drive switched by a MOSFET and worked out to about 7.5 amps between the 6 parallel LEDs off fresh cells. So much for its 'claims'.
Let water in at the switch so fitted a waterproof switch, Next tried 4 ultra high discharge cells and fried the LEDs plus the driver. Not to be thwarted I fitted new LEDs and a better driver board from Fasttech, now its isn't a bad torch.
I love messing.
The keyring lights the Chinese give away with orders are useful as you always have your keys so you always have a light, but yet again they have to score own goals by making some of them with coloured LEDs.
My avatar is a poor likeness.