I standardized as well with CR-123's; Princeton Tec Apex Pro headlamp and a Zebralight H30. Other flashlights are CR-123A as well.

For AA folks, it would be hard to beat the newest Zebralight H501. 3.3 lumens for 3.5 days or 96 lumens for 2.5 hours, on a single AA, with a nice smooth flood pattern.

I use my H30 on the lowest setting (4 lumens, 3.7 days) as a tent light as well.