Popular Photography has an extremely useful review of double A batteries in their June issue. I'm surprised that I haven't seen this examined by other photography magazines. We all use them, after all. The results are not entirely surprising-- it turns out that you get what you pay for. For example, among the rechargable batteries tested, PopPhoto says the Energizer "15 minute charger" are a best buy. They're also the most expensive of the bunch, at $29.87 for four batteries and the charger.
Of the disposable batteries, Energizer's E2 Lithium (seen above) costs more than twice as much as the next most expensive, at $16.84 for a pack of eight, but they last nearly 4 times as long! I can attest to this, as I recently bought some of these to use in my pocket camera. Granted I don't use that camera very often, but I can't remember the last time I had to swap these batteries out.
On a completely unrelated note, I suddenly have the song Battery, by Metallica, in my head. Smashing through the boundaries, lunacy has found me... cannot stop the battery! Yes, my head is a strange place.
Photo details: Nikon D50 with 60mm Nikon Micro lens, 1/640sec at f6.3. If you click on the photo you can see a much larger version.