Sanyo also has a new eneloop that is a little lower capacity but has even better cold temperature characteristics.
I have 1650mAH sanyo NiMH from 1999 that I still use in kids toys.
Avoid any fast chargers, those 15 minute battery cookers, with low self discharge nimh you can just carry extras knowing they are always ready. I've taken eneloops that sat for 6 months to a year and ran them through 450+ pictures in our camera, Lithium just under 500 so close enough in performance to make lithium unneeded anymore.
Avoid chargers that charge in pairs, any charger should charge each battery independently. Avoid ones that just trickle charge (take 8 hours or more), charging too slow or too fast isn't best for their health.

Second the recommend on maha.