According to the December 2011 issue of Consumer Reports, the longest-lasting battery brand is the Energizer Ultimate Lithium battery. This is based on a study of AA batteries.
Consumer Reports tested AA batteries using high-draining digital cameras and low-draining flashlights. Energizer Ultimate Lithium batteries took the most photos before dying (1,266 photos). The quickest-to-die battery tested was the Walgreens Supercell alkaline, which took only 133 photos. The longest-lasting alkaline battery brand was Duracell Ultra Advanced, and the longest-lasting rechargeable battery was Duracell Precharged.
As a whole, lithium batteries lasted longer than alkaline, but they also cost more than alkaline batteries. Rechargeable batteries are the most environmentally friendly choice.