What is an enloop battery?
Which one is the best?
Where is the best place to get them?
Thanks, MikieG
An eneloop is a rechargeable AA battery made by Sanyo. It has the advantage of being low self discharge, which means you can charge it, put it in a light and it will still be charged 3 months from now.
Costco has some great prices on them, 20$ for 10.
Now to just find a costco!
What brand are they?
Eneloop is the brand, they actually make lots of other batteries too. (AA, AAA, C, D, etc.)
‘eneloop’ is the brand. They are manufactured by Sanyo and the broader type is ‘low self-discharge’.
Amazon has a good selection of Eneloops at prices not quite as good as Costco. The XX Eneloops will give you longer runtimes, but are pricey. And no, you don’t have to use a charger that is branded “Eneloop”. The Amazon site is also chatty about the Eneloop “story”, which may be interesting.
If you order an 8-pack and a 4-pack, you’ll get free shipping (total order over $25). The 8-pack was $19.10 when I wrote this. The Amazon price may change at any time, up or down.
Edit: You will want to watch this video to see how Eneloops can be a meaningful part of your life: 
http://www.amazon.com/gp/mpd/permalink/m3CX0LCHNRUQHH/ref=ent_fb_link
Check this out;
Adorama has Eneloop AA's on sale:
Sanyo "New" 1500 Eneloop AA Pre-Charged Rechargeable NiMH (1900 mAh) Batteries (8 Pack)- (HR-3UTGA) - $17.19 (free shipping in USA).