Eneloops are known as low self-discharge, a newer breed of NiMH batteries that can hold 80% of their charge for a year or longer.
Standard NiMH batteries only hold their charge for one or two months.
So if you only use your camera occasionally, and a few months elapse between uses, Eneloops might be a good choice.
However, realize that the Eneloops trade the convenience of holding a charge for capacity. You can buy standard NiMH batteries that are rated for 2,700mAH, while the Eneloops are only rated for 2,000mAH.
The mAH rating is the capacity of the battery; how much energy it can deliver.
In the low discharge types, Eneloops are among the best batteries. For standard NiMH batteries, it is hard to beat PowerEx 2700s.
There is one serious issue with using NiMH batteries though. They cannot deliver a large amount of current - at least not as much as the other type batteries.
Duracell non-rechargeable Alkaline batteries for instance, have about a 2,000mAH to 2,400mAH capacity, but they can deliver a higher instantaneous amount of current than the NiMH batteries can.
And the non-rechargeable Energizer Ultimate Lithium batteries (Lithium Iron Disulfide) are the best, in terms of capacity; 3,000mAH+, and can also deliver more instantaneous current than the others. The downside of these batteries however are they are non-rechargeable.
Another type battery you may find in the AA size are Lithium-ion batteries. While most of the battery packs that come with cameras use Lithium-ion or Lithium-Polymer batteries, they are NOT appropriate for use in the AA size as at 3.6V, they are over twice the voltage as the other batteries.
So never use rechargeable Lithium batteries in the AA size for your camera, or you will damage it.
To summarize then, you essentially have four choices for AA batteries - and I would use those specific brands;
1. Duracell Alkaline. They have a 2,400mAH rating and can output a high instantaneous current.
2. Energizer Ultimate Lithium, which has 3,000+ mAH, rating and can also output a high instantaneous current.
3. Sanyo Eneloop Low Self Discharge rechargeable NiMH batteries - having a 2,000mAH rating, have the least capacity and a lower instantaneous current rating. They do however last over a year between charges if unused and in storage.
4.Maha/PowerEx 2700 for standard discharge rechargeable NiMH batteries. At 2,700mAH, they come in second to the Energizer Ultimate Lithium batteries in capacity, but only last a month or two between charges in storage conditions.
Which one is right for your camera then?
Some cameras use two AA batteries. These cameras may have difficulty with using NiMH batteries, especially when in flash mode as the two batteries may not be able to deliver the peak current required by the camera.
If the camera uses 4 AA batteries, this may not be as much of an issue.
Other than that, you should be able to use any of the above described batteries. Which one is right for you primarily depends on your budget and time between uses.
I have a camera that takes 2 AA batteries. I keep it in my car for times that I otherwise find myself without a camera. Since it may be months between uses, I could use Sanyo Eneloops. However, I prefer Energizer Ultimate Lithium batteries as the camera only has 2 AA batteries, and these batteries offer more performance for that camera.
But if I use the camera significantly in one setting - when I go through more than one set of batteries, I may swap out Alkaline for the Lithium during that use. However before the camera goes back into semi-storage in the car, I will again load it up with Lithiums.
If you are using a flash, again the Energizer Ultimate Lithiums or even the Duracell Alkaline batteries will offer quicker recycle times as they can output higher instantaneous current than the NiMH batteries can. The NiMH batteries will just take a bit longer to recharge the flash after each cycle.
What you use depends on your preferences.