db-- Union Carbide sold/spun-off their battery division, it is now a part of Energizer Holdings Inc.
My prejudices:
N style: these are all alkaline, no rechargables on market yet (darn).
1.) Kodak KN; 2.) Duracell MN9100; 3.) Rayovac 810; 4.) Eveready (now Energizer) E90; 5.) Varta 4001; 6.) Toshiba LR1; 7.) Panasonic AM5. The first two are all I would really care to look for--- they are not all that much more expensive than the rest.
AA, AAA, C or D: get the NIMH and a NIMH charger, you'll never regret it--
1.) Kodak NIMH Rechargable; 2.) Energizer "e2"; 3.) Rayovac Accu; 4.) Maha or Quest Gold or Nexcell (all in this category are pretty good).
If you don't yet have a NIMH charger, but you have an alkaline charging system--
5.) Rayovac Renewal. This was the first alkaline rechargable, and they still make it seven years later, and they keep on making the batteries even better.
If you don't yet use rechargables: (plain alkalines)
6.) Energizer; 7.) Duracell; 8.) Kodak. These are all, in my opinion, fairly comparable, with Energizer just a tiny bit ahead, but Duracell and Kodak so close behind, it doesn't really seem right to rank them behind in any way.
Not recommended under Any but Dire circumstances: KMart, Walmart, Albertsons, Target, Sears branded alkalines. These are usually made by the larger companies like Energizer and Rayovac for the chains, BUT freshness is no longer the responsibility of the jobber; just the inventory practices of the chain or, in most cases, the store.
When I worked at a Sears store a decade ago, one of my weekly duties in my department was to dust the batteries. It hasn't changed all that much since.
On a side note, I've always thought someone should market a "battery condom": a thin sealable vinyl jacket with two tiny metallic discs/rivets built in to make the contacts... so that if a battery fails and oozes out of its casing, your precious camera or calculator or whatever is never exposed or damaged. Maybe the jacket would be clear and have a neutralizing chemical coating inside it which would turn red or something if exposed to electrolyte.
I can see the advertising copy now: "A Durex for your Duracells! Don't let a burst do the worst!"
...Oh well; maybe not. :-)