I would say all but my headlamp, and keychain lights are CR123a.

I want to get a nice AA and/or AAA flashlight too since I have those batteries for other things and diversification is good + if I`m at someone elses house they most likely will have those batteries.

So, what's everyone's favorite AA or AAA light? Size requirements are something that fit on your belt. Similar to a surefire G2 size smaller but no larger.