Yeah, I tried to standardize on AA batteries but failed. Some goodie would come along in other than AA and I went for it. GPS and LED flashlights are AA. My headlamp is AAA; both lights for my handgun and shotgun are CR123A. A couple pocket lights are AAA and the DR light on my keyring is a coin-cell.

One reason to standardize on AA NiMH rechargables is that my Goal Zero solar panel uses AA NiMH batteries as part of its system. That's one very good reason to standardize on AA batteries. YMMV