Cygolite Dual Cross NiMH.

the NiMH last a long time, is impervious to cold (actually last longer w/ more intensity in cold) and it is a SUPER bright LED with 4hrs run time on strong. I RARELY use the super high beam. Use the low 2 choices when there's lots of ambient light and only the super strong in the pitch, pitch black just because I can.

It's around $150.