There are 3 kind of Eneloops: Eneloop Lite, Eneloop and Eneloop XX.
Eneloop Lite:
AAA - 600mAh, 2000 charges
AA - 1000mAh, 2000 charges
Eneloop: (the colored ones are in this category too)
AAA - 800mAh, 1500 charges
AA - 2000mAh, 1500 charges
Eneloop XX:
AA - 2500mAh, 500 charges
You have to choose the ones that fit your needs better. I prefer the regular Eneloops. But if you want to use them in a high end camera or a powerful flashlight, they might do the trick.
It is also good to know that white top Duracell batteries are also re-branded Eneloops, the so called
[lmgtfy]Duraloops[/lmgtfy][/b], so if you have trouble finding the real ones, these are the same thing only wearing different "clothes".
EDIT:
OK, I see that Gareth beat me to it.
I have a few of the Eneloop Lite AAAs and they work great (for a AAA flashlight), I hardly notice the 200mAh difference, and am glad to know they will give me 500 more charges then the regular ones. They are about 20% cheaper too.