Just as important as the battery is its power source. I have gone to rechargeable batts wherever possible - Nimh (preferably Eneloops) or li-ion (mostly 18650s) and lithium primary batteries when long term storage is an issue. Alkaline batteries will almost inevitably leak, usually in your most expensive gear.

Whatever your choice for a light, if it isn't at hand when you need it, it is useless...