Mag85 currently, though "normally" it's a Surefire A2. But the Mag85 is a good one, too. I built mine with AW's 3-level switch and it works great. I use it on low when we are on the wooded part of our walk and then switch it to medium or 100% when we get to more open areas. Still brings a boyish grin to my face to see how much scenery it lights up. :naughty:
(A word of warning to anyone who doesn't have a Mag85 yet: after a couple of weeks you get used to all that power. The other night I was charging its cells, so I took my Fenix L1D-CE instead and it seemed just anemic. Well, sure it's still a small and handy light, but when you are used to lighting up the trail well over a hundred meters ahead, anything less will seem weak.)