If you want to stay with AA you might want to check out some of the new lights with the latest generation R5 led. I have one (not for biking though) and it is considerably brighter than the Ld2, with a much larger hot spot, which means that more of the road get lit up. The downside is that they don't throw as far as the older emitters, but personally I don't think it's much of as issue.


As for best 'bang for the buck', I think that's with lights that are powered by 18650 li-ion rechargables. Once you get over the initial outlay for the the batteries and charger you not only get a considerably brighter light than with AA batteries, but you can also upgrade your light easily and inexpensively when new LEDs come out by simply buying a new drop-in. (A drop-in is akin to a bulb.)

I like Solarforce lights as they are inexpensive and well made. You can get the light for $34 shipped. The charger and batteries should cost another 25-30 dollars.

http://www.sbflashlights.com/Solarfo...rce-L2-p4.html - I'd go for the 5 mode (it has strobe for daylight riding if you need it) in 4.2v. Whatever you do, if you choose one of these lights make sure you get a drop-in that's 4.2v as it will be much brighter on one battery than the 18v ones will.