Duracell batteries are the ones I always reach for. While they may not be the cheapest, I believe they are still the most economical. We use batteries in our T.V. remotes, our clocks, some of my husband's guitar gadgets, grandkid's toys, flashlights, and all the usual kind of stuff.
When I buy an eight pack of AA batteries for $6.99 that is less than one dollar each. For that, I power all those little gadgets for a long time. I've never actually figured out how long exactly they last, but I think I will next time I pop in a new one.
We used to try the economy batteries, and I even used rechargeable ones for awhile. The trouble with the rechargeables was that my kids tended to lose them. They are older now, but not really that much more responsible. I just gave up on them and now trust my gadgets and theirs to Duracell.
Duracell comes in all sizes from D to AAA. that makes it perfect for anything and everything you will need batteries for.